I own both and have modded both (so am not being biased) but feel there are so many better mods for FO3 than there are for vegas, perhaps it could be that vegas hasnt been out for as long? i dont know but i know NOW fallout 3 for me is the far superior game. Other aspects i take into account are the setting, i feel fo3's setting is so much more varied and exciting than vegas's dessert. The story also i think is better and more plausable compared to vegas's you get shot in the head and a robot digs you up when your trying to deliver something story. But vegas takes the point for craftable guns and items, also gun mods. But again this and more is possibe with mods in fallout 3. I ideally wanted fo3's story and setting with vegas's features and with mods, i believe i can. Heres the mods i use which i think make fallout 3 my favourite:
Spoiler
[X] Fallout3.esm
[X] Anchorage.esm
[X] ThePitt.esm
[X] BrokenSteel.esm
[X] PointLookout.esm
[X] Zeta.esm
[X] Unofficial Fallout 3 Patch.esm
[X] CRAFT.esm
[X] Project Beauty.esm
[X] ArefuExpandedByAzar.esm
[X] Vault 101 Revisited.esm
[X] Advanced Recon Tech.esm
[X] EVE.esm
[X] Apocalypse Armory.esm
[X] Mart's Mutant Mod.esm
[X] Arwen_Core.esm
[X] Companion Core.esm
[X] RobCo Certified v2.esm
[X] Enhanced Weather - Rain and Snow.esm
[X] Xepha's Dynamic Weather.esm
[X] DCInteriors_ComboEdition.esm
[X] SeducingWomen.esm
[X] EnhancedChildren.esm
[X] AliciasCuteShop.esm
[X] RH_IRONSIGHTS.esm
[X] Zumbs' Overhauled Real Time Security.esm
[X] Unofficial Fallout 3 Patch - Operation Anchorage.esp
[X] Unofficial Fallout 3 Patch - The Pitt.esp
[X] Unofficial Fallout 3 Patch - Point Lookout.esp
[X] Unofficial Fallout 3 Patch - Mothership Zeta.esp
[X] DarNifiedUIF3.esp
[X] Project Beauty- Broken Steel.esp
[X] Project Beauty- Point Lookout.esp
[X] YearlingsGlasses.esp
[X] CRAFT - Activation Perk.esp
[X] RH_IronSights_Basic_VanillaPlugin.esp
[X] RH_IronSights_Basic_AnchoragePlugin.esp
[X] RH_IronSights_Basic_PittPlugin.esp
[X] RH_IronSights_Basic_BrokenSteelPlugin.esp
[X] RH_IronSights_Basic_PointLookoutPlugin.esp
[X] RH_IronSights_Basic_ZetaPlugin.esp
[X] RH_IronSights_Pitt_NewRifleSights.esp
[X] RH_IronSights_PL_NewItems.esp
[X] ArefuExpandedByAzar-Radio.esp
[X] GNR Enhanced.esp
[X] GeneratorSound.esp
[X] UPP - Pack 1.esp
[X] UPP - Pack 2.esp
[X] UPP - Original Perks.esp
[X] UPP - Experience Perks.esp
[X] UPP - Quest Perks.esp
[X] UPP - Beverage Perks.esp
[X] MegatonContracts.esp
[X] TecVault.esp
[X] DisplayedAmmoWeight.esp
[X] MaintenanceShed.esp
[ ] CrowdedCities_v2.esp
[X] CrowdedCities_v2_lessNPCs.esp
[X] MTC Wasteland Travellers.esp
[X] MTC Wasteland Travellers (Optional)- Crowded Cities less NPCs.esp
[ ] MTC Wasteland Travellers (Optional)- Crowded Cities.esp
[X] AliciasCuteShopDoorOverride.esp
[X] ArefuExpandedByAzar-FixMisc.esp
[X] ArefuExpandedByAzar-FixOptRemOld.esp
[X] ArefuExpandedByAzar-FixOptAddNew.esp
[X] ArefuExpandedByAzar-FixEyes.esp
[X] DCInteriors_DLC_Collectables.esp
[X] Location 1 (Megaton-V101).esp
[X] megalight.esp
[X] UndergroundHideout.esp
[X] Vault 89 (player home) V1-35.esp
[X] WeightAmmo.esp
[X] Apocalypse Armory.esp
[X] Apocalypse Armory - DLC Enhancements.esp
[X] Apocalypse Armory - Optional Historical Names.esp
[X] WeaponModKits.esp
[X] WeaponModKits - OperationAnchorage.esp
[X] WeaponModKits - ThePitt.esp
[X] WeaponModKits - BrokenSteel.esp
[X] WeaponModKits - PointLookout.esp
[X] WeaponModKits - Zeta.esp
[X] WMK-RH IronSights.esp
[X] Apocalypse Armory + WMK.esp
[X] MissingUniqueWeapons-Standard-BS+PL.esp
[X] Advanced Recon Gear.esp
[X] Advanced Recon Tech.esp
[X] MissingUniqueArmorClothing-Enhanced-NSF.esp
[X] Stealthboy Recon Armor - CRAFT.esp
[X] Brahmin Dairy Products.esp
[ ] Childhood Beginning.esp
[X] KarmaRevamp1010.esp
[ ] WeightMisk.esp
[ ] WeightMed.esp
[ ] ZORTS - Content Destruction - Normal.esp
[X] ZORTS - Custom HP.esp
[ ] ZORTS - Lockbash only.esp
[X] ZORTS - Enable minigames.esp
[X] Companion Core DLC Addon.esp
[X] RobCo Certified v2 Mechanist's Edition.esp
[X] RobCo Certified v2 Zeta Addon.esp
[X] Mr Smith's Scrapyard.esp
[X] EVE.esp
[X] EVE Operation Anchorage.esp
[X] Apocalypse Armory + EVE.esp
[X] RH_EVE_Bridge.esp
[X] Mart's Mutant Mod.esp
[X] Mart's Mutant Mod - DLC Anchorage.esp
[X] Mart's Mutant Mod - DLC The Pitt.esp
[X] Mart's Mutant Mod - DLC Broken Steel.esp
[X] Mart's Mutant Mod - DLC Point Lookout.esp
[X] Mart's Mutant Mod - DLC Zeta.esp
[X] Mart's Mutant Mod - Zones Respawn.esp
[ ] Mart's Mutant Mod - Tougher Traders.esp
[ ] Mart's Mutant Mod - Natural Selection.esp
[X] Mart's Mutant Mod - Master Menu Module.esp
[X] Mart's Mutant Mod - Project Beauty.esp
[X] SeducedDLC03.esp
[X] SeducingWomen_patch_156.esp
[X] Arwen_Realism_Core.esp
[X] Arwen_GOTY_Realism_Core.esp
[X] Arwen_Hard-Core.esp
[X] Arwen_GOTY_Hard-Core.esp
[X] Arwen_Encumbrance.esp
[X] Arwen_Med-Tec.esp
[X] Arwen_GOTY_Med-Tec.esp
[X] Arwen_MMM_Med-Tec_Patch.esp
[X] Arwen_EVE_Patch.esp
[X] Arwen_Brahamin_Med-Tec_Patch.esp
[X] ColeensTent.esp
[X] Owned!.esp
[X] Whose been sleeping in my Bed.esp
[X] NoFastTravel.esp
[X] dD - Enhanced Blood Main.esp
[ ] dD-Screen Blood Vanilla.esp
[X] Enhanced Weather - Rain and Snow in Fallout.esp
[X] Enhanced Weather - Radioactive Rain and Snow Plugin.esp
[X] Enhanced Weather - Weather Sounds in Interiors.esp
[X] Enhanced Weather - Sneak Bonus during Storms.esp
[X] Enhanced Weather - REBOOT.esp
[X] Xepha's Dynamic Weather - Main.esp
[X] Xepha's Dynamic Weather - Anchorage.esp
[X] Xepha's Dynamic Weather - The Pitt.esp
[X] Xepha's Dynamic Weather - Broken Steel.esp
[X] Xepha's Dynamic Weather - Point Lookout.esp
[X] RobCo Certified v2 EVE.esp
[ ] ColeensTentNoStorage.esp
[X] Merged Patch.esp
[X] Fallout3.esm
[X] Anchorage.esm
[X] ThePitt.esm
[X] BrokenSteel.esm
[X] PointLookout.esm
[X] Zeta.esm
[X] Unofficial Fallout 3 Patch.esm
[X] CRAFT.esm
[X] Project Beauty.esm
[X] ArefuExpandedByAzar.esm
[X] Vault 101 Revisited.esm
[X] Advanced Recon Tech.esm
[X] EVE.esm
[X] Apocalypse Armory.esm
[X] Mart's Mutant Mod.esm
[X] Arwen_Core.esm
[X] Companion Core.esm
[X] RobCo Certified v2.esm
[X] Enhanced Weather - Rain and Snow.esm
[X] Xepha's Dynamic Weather.esm
[X] DCInteriors_ComboEdition.esm
[X] SeducingWomen.esm
[X] EnhancedChildren.esm
[X] AliciasCuteShop.esm
[X] RH_IRONSIGHTS.esm
[X] Zumbs' Overhauled Real Time Security.esm
[X] Unofficial Fallout 3 Patch - Operation Anchorage.esp
[X] Unofficial Fallout 3 Patch - The Pitt.esp
[X] Unofficial Fallout 3 Patch - Point Lookout.esp
[X] Unofficial Fallout 3 Patch - Mothership Zeta.esp
[X] DarNifiedUIF3.esp
[X] Project Beauty- Broken Steel.esp
[X] Project Beauty- Point Lookout.esp
[X] YearlingsGlasses.esp
[X] CRAFT - Activation Perk.esp
[X] RH_IronSights_Basic_VanillaPlugin.esp
[X] RH_IronSights_Basic_AnchoragePlugin.esp
[X] RH_IronSights_Basic_PittPlugin.esp
[X] RH_IronSights_Basic_BrokenSteelPlugin.esp
[X] RH_IronSights_Basic_PointLookoutPlugin.esp
[X] RH_IronSights_Basic_ZetaPlugin.esp
[X] RH_IronSights_Pitt_NewRifleSights.esp
[X] RH_IronSights_PL_NewItems.esp
[X] ArefuExpandedByAzar-Radio.esp
[X] GNR Enhanced.esp
[X] GeneratorSound.esp
[X] UPP - Pack 1.esp
[X] UPP - Pack 2.esp
[X] UPP - Original Perks.esp
[X] UPP - Experience Perks.esp
[X] UPP - Quest Perks.esp
[X] UPP - Beverage Perks.esp
[X] MegatonContracts.esp
[X] TecVault.esp
[X] DisplayedAmmoWeight.esp
[X] MaintenanceShed.esp
[ ] CrowdedCities_v2.esp
[X] CrowdedCities_v2_lessNPCs.esp
[X] MTC Wasteland Travellers.esp
[X] MTC Wasteland Travellers (Optional)- Crowded Cities less NPCs.esp
[ ] MTC Wasteland Travellers (Optional)- Crowded Cities.esp
[X] AliciasCuteShopDoorOverride.esp
[X] ArefuExpandedByAzar-FixMisc.esp
[X] ArefuExpandedByAzar-FixOptRemOld.esp
[X] ArefuExpandedByAzar-FixOptAddNew.esp
[X] ArefuExpandedByAzar-FixEyes.esp
[X] DCInteriors_DLC_Collectables.esp
[X] Location 1 (Megaton-V101).esp
[X] megalight.esp
[X] UndergroundHideout.esp
[X] Vault 89 (player home) V1-35.esp
[X] WeightAmmo.esp
[X] Apocalypse Armory.esp
[X] Apocalypse Armory - DLC Enhancements.esp
[X] Apocalypse Armory - Optional Historical Names.esp
[X] WeaponModKits.esp
[X] WeaponModKits - OperationAnchorage.esp
[X] WeaponModKits - ThePitt.esp
[X] WeaponModKits - BrokenSteel.esp
[X] WeaponModKits - PointLookout.esp
[X] WeaponModKits - Zeta.esp
[X] WMK-RH IronSights.esp
[X] Apocalypse Armory + WMK.esp
[X] MissingUniqueWeapons-Standard-BS+PL.esp
[X] Advanced Recon Gear.esp
[X] Advanced Recon Tech.esp
[X] MissingUniqueArmorClothing-Enhanced-NSF.esp
[X] Stealthboy Recon Armor - CRAFT.esp
[X] Brahmin Dairy Products.esp
[ ] Childhood Beginning.esp
[X] KarmaRevamp1010.esp
[ ] WeightMisk.esp
[ ] WeightMed.esp
[ ] ZORTS - Content Destruction - Normal.esp
[X] ZORTS - Custom HP.esp
[ ] ZORTS - Lockbash only.esp
[X] ZORTS - Enable minigames.esp
[X] Companion Core DLC Addon.esp
[X] RobCo Certified v2 Mechanist's Edition.esp
[X] RobCo Certified v2 Zeta Addon.esp
[X] Mr Smith's Scrapyard.esp
[X] EVE.esp
[X] EVE Operation Anchorage.esp
[X] Apocalypse Armory + EVE.esp
[X] RH_EVE_Bridge.esp
[X] Mart's Mutant Mod.esp
[X] Mart's Mutant Mod - DLC Anchorage.esp
[X] Mart's Mutant Mod - DLC The Pitt.esp
[X] Mart's Mutant Mod - DLC Broken Steel.esp
[X] Mart's Mutant Mod - DLC Point Lookout.esp
[X] Mart's Mutant Mod - DLC Zeta.esp
[X] Mart's Mutant Mod - Zones Respawn.esp
[ ] Mart's Mutant Mod - Tougher Traders.esp
[ ] Mart's Mutant Mod - Natural Selection.esp
[X] Mart's Mutant Mod - Master Menu Module.esp
[X] Mart's Mutant Mod - Project Beauty.esp
[X] SeducedDLC03.esp
[X] SeducingWomen_patch_156.esp
[X] Arwen_Realism_Core.esp
[X] Arwen_GOTY_Realism_Core.esp
[X] Arwen_Hard-Core.esp
[X] Arwen_GOTY_Hard-Core.esp
[X] Arwen_Encumbrance.esp
[X] Arwen_Med-Tec.esp
[X] Arwen_GOTY_Med-Tec.esp
[X] Arwen_MMM_Med-Tec_Patch.esp
[X] Arwen_EVE_Patch.esp
[X] Arwen_Brahamin_Med-Tec_Patch.esp
[X] ColeensTent.esp
[X] Owned!.esp
[X] Whose been sleeping in my Bed.esp
[X] NoFastTravel.esp
[X] dD - Enhanced Blood Main.esp
[ ] dD-Screen Blood Vanilla.esp
[X] Enhanced Weather - Rain and Snow in Fallout.esp
[X] Enhanced Weather - Radioactive Rain and Snow Plugin.esp
[X] Enhanced Weather - Weather Sounds in Interiors.esp
[X] Enhanced Weather - Sneak Bonus during Storms.esp
[X] Enhanced Weather - REBOOT.esp
[X] Xepha's Dynamic Weather - Main.esp
[X] Xepha's Dynamic Weather - Anchorage.esp
[X] Xepha's Dynamic Weather - The Pitt.esp
[X] Xepha's Dynamic Weather - Broken Steel.esp
[X] Xepha's Dynamic Weather - Point Lookout.esp
[X] RobCo Certified v2 EVE.esp
[ ] ColeensTentNoStorage.esp
[X] Merged Patch.esp
I also use NMC's texture pack and some sound mods.
I know each game has its different mods which effect different things, but taking into consideration which game you prefer when mods are used, what do you think?