For the Main, Tri-Stringer. Honorable mention to Goo Tuber.
I'm a fan of Stringers' versatility in general and main the REEF-LUXes, but I prefer the Tri-Stringer overall since it has more range. I just wish it was a bit faster, a bit stronger, and/or a bit better.
For the Sub, Fizzy Bomb. Burst Bomb is another candidate.
Fizzy Bomb's charge mechanic, multiple non-lethal explosions, and overall versatility are what make it my favorite. My one wish is that they scrap the gimmick of using motion controls to charge it faster, and just have it charge at a set rate.
For the Special, Killer Wail 5.1. Runners-up are Reefslider and Tenta Missiles, but only with some reworks/rebalancing.
Killer Wail 5.1 is simply perfect. Need location and/or chip damage? Want to support your team at a distance? Might I recommend:
The special is easily the most balanced in the game, it's brilliant in its simplicity, and it's very easy to dodge if you're not already being pressured by the enemy. Combos brilliantly with Bamboo, Rapid Pro Deco, Nova, and Stringer. As long as you have your painting needs covered, you couldn't ask for a better tool.