so i have completed mothership zeta crew for now (can't wait for more) and alton main quest (as the side quests don't work)-comming back to that later on-but i was wondering if there are anymore good quest mods out there that i should try thanks!

Here's a few...

A Quest for Heaven series http://fallout3.nexusmods.com/downloads/file.php?id=10208, http://fallout3.nexusmods.com/downloads/file.php?id=12887 and http://fallout3.nexusmods.com/downloads/file.php?id=15488
Quest mods from http://fallout3.nexusmods.com/modules/members/index.php?id=137055 (I particularly enjoy In the Shadow of the Swamp and The Mantis Imperative)
http://fallout3.nexusmods.com/downloads/file.php?id=13308
http://fallout3.nexusmods.com/downloads/file.php?id=15513
http://fallout3.nexusmods.com/downloads/file.php?id=9366

thanks! I think i will do the quest for heaven series, puce moose's mods and vault 101 revisited although im not sure about the other two...

http://fallout3.nexusmods.com/downloads/file.php?id=6270 (and if you have Oblivion you owe it to yourself to try out their Nehrim mod )
Puce Moose etc

Quest for Heaven 1 and 2 are good, but I'm not so sure about 3. I tried the 'preview' of it and it seemed to be trying to turn Fallout into Half Life and had got itself into an arms race of creating ever more ridiculously-powerful weapons to fight ever more ridiculously-tough enemies.

You can't go wrong with Puce Moose if you like interesting stories and puzzles.