Do you use fatmans and incinerators (silly ridiculous weapons), or realistic weapons?

I use a .45 pistol and a 12 gauge hunting shotgun (like the 1911 and 870 that I own in real life).

So what do you use?

Depends on the character. I like realistic weapons but the fictional ones (plasma, fatmans, power fists) are way more fun to use.

I use revolvers and Dinner Bell.

I eventually get Lucky in all playthroughs.

If you know what I mean...

Give me a rifle with a scope and a shotgun, and I am a happy man.

I use dinnerbell too

Lucky
Hunting Shotgun+
Chance's Knife
Trail Carbine+

I actually prefer semi-auto pistols to revolvers simply because most of the time when I pull out a single hand weapon I'm going to be moving around a lot and 6 shots and a slow reload isn't ideal for that sort of thing, but since lucky has such high crit and benefits from cowboy it's still probably the best sidearm option for my character. The hunting shotgun is now what I use to deal with fast moving enemies anyway. And Stay Back! is amongst my favorite perks since I don't use vats.

a rifle and a sawn-off, anything else is just a toy.

Anti materiel rifle i really like it and in times of need Alien Blaster.

AMR
AER14 Prototype
Gauss Rifle
ALSiD
GMG

I love guns, ew, and explosives.. Pretty much all that fall in those categories; but these are my favorites.

Depends on the character, but my 'default' character (the build I gravitate towards if I'm not actively roleplaying) uses:

All-American
Assault Carbine
Gobi Campaign Scout Rifle
Sleepytyme
Katana/Greased Lightning
Paladin Toaster

I use the WMX mod so I can silence the Gobi rifle and assault carbine too.

As like others it really depends on your character. But most of the time I have my character very Proficient in Guns and Explosives.
My Standard Loadout
- Hunting Rifle+
- .45 auto pistol
- Red Glare (dlc)

Lucky
Gobi scout rifle
GRA AMR+
Trail Carbine+

Oh Baby! or any other melee weapon up until I get that as my primary weapon, I use the Hunting Shotgun as a secondary weapon

Q35 and this machine are my bread and butter and holo rifle for everything else (pre dlc gauss rifle , tesla beaton before the patch that made it obsolete) I like mysterious magnum and c.o.s rifle.

1. Marksman Carbine/All American
2. .45++/ALSID
3.Trail Carbine+
4.Laser Rifle+++
5.Thump Thump
6. Ratslayer
7. Lucky

Oh yeah the RatSlayer comes with me for a while as well, since you know, you can't get up close and personal with everything

By your qualification, I use 'realistic' weapons. I don't use Energy Weapons and I don't use anything that might have, in Fallout 3, been considered a Big Gun.

Without any mods dropped on the game, I prefer to use a .45 Auto. With mods, I prefer a .45-70 LeMat revolver.