The option to vote "I don't use this kind of gun unless I'm forced to" is missing from all three. Alternatively, simple the possibility to not have to vote on all items.

Infiltrator
Tri-beam laser rifle
Heavy incinerator

If I had to pick just one it would be the incinerator

-sawed-off shotgun
-alien blaster
-rock it launcher

i am terrible sniper so i go close range and if i have to use long distance guns, then i use scoped 44 or lincoln repeater.

those 3 guns at my list are in my opinion the coolest guns ever If i need to take out Super mutant behemot or deathclaw then i use mines or something. I don't waste bullets if possible. :fallout:

the blackhawk?

Hunting Rifle because its iconic to the game; its Fallout 3 personified. But I do like the Infiltrator.
I don't really like energy weapons but the Plasma rifle or Gauss rifle although slow are very powerful and consequently fun to use.
Again the big-guns are not for me but I enjoy using the Gatling gun from time to time.

The Combat Shotgun is my favourite weapon ever! Jesus, it's so powerful and it looks so bad ass taking on a super mutant and shooting it's head off with Bloody Mess.

*orgisms*

I voted for the Infiltrater, Gauss Rifle and Fatman.

My among my favourites are The Terrible Shotgun, Plasma Rifle, Gatling Lazor, Drone Cannon X-EB, Alien Atomiser, Alien Disintigrater, and the Tri Lazor.
I like most of the guns in Fallout 3.