I would say everybody has it's own good things, but I wont tell what trunks can do and what no because it's exploit ^^.
Piccolo has SBC, Lasereye, that a lot of balls-to target thingy, and masenko if you like PS with your own ki.
Trunks only have Finishing Buster in SSJ form that is useful.
Gohan has shield, khh in SSJ, nothing special.
Buu can regenerate his life, make almost 100k every frag if pro using on candy-ray, mouthbeam.
Goku has spirit bomb, can teleport on SSJ charging any beam, has homing torpedos and funny think - Sunlight technique :laff:
Krillin <--- I would call him n00b on first state, but when he transforms, beware of him.Has destruction disc, can make blast on everybody in server if that beam notices, has Sunlight technique and kamehame, SUPER SPEED
You would know pretty much of that if you could test them all.