@Prettzl : where is the love for the flak cannon ? Seriously tho, a lot of UT guns are extremely well designed and effective in their role, I personnaly love UT99's sniper rifle for how heashots were satisfying, the UT99/2k4 flak cannons, and of course the shock combos and their incredibly badass explosion sound. The bio-sludge rifle is also pretty hilarious (shoot green alien poop to your opponents !). The UT serie really had great gun design/animation/user feedback, as well as super brutal sound effects.
The double fire mode design is in particular a very interesting feature, allowing guns to be used for different roles at once (zone denial, close range damage, etc.). The UT2k4 link gun is in that regard a perfect example, having an high rof low damaging projectile attack (similar to AoT's multi cannon autofire), as well as a beam attack that would either act as the Q3 lg when aimed at an ennemy, and as an healing ray when linked to a friendly. It also have a boost feature were different users linking their rays to each other would get a strong damage buff. That's a lot of depth and possibilities in only one weapon, and thanks to the ray's color code, it avoided being confusing to a new user. It definitely wasn't my favorite gun in the game by far but I think it stands as a great example of creativeand efficient weapon design.
Right now i didn't see a real zone denial weapon in AoT (similar to the T:A fractals, UT's bio rifle or Q3 grenades), but of course its balance would be an issue (e.g. T:A fractals were quite op when used cleverly), especially in indoor flag bases. The area of effect and duration would be in that matter extremely important parameters to consider for it to be both useful and fair.
Another idea : I think everyone remembers Half Life's snarks ( https://33.media.tumblr.com/tumblr_ly2ww9AOdq1qcb7k0o1_500.gif ), those were funny and unpredictable zone denial options :>