Dreamin sun is a purty funny shoujo manga, I love the faces and how sweet and stupid it can be XD. It really isnt a "gag" manga but still funny. But one of my topes is full metal panic overload, its totally (somewhat) of its main plot. Its very funny. Lets not forget school rumble either.
funny manga with plots (sorry): ane doki (shounen/ecchi), Usotsuki lily (gender-bender/shoujo), Popcorn Avatar (shounen/ecchi/action). sorry those all have plots lol.