well personally Gintama is my favourite anime atm. although its a story about a samurai with 2 assistant that doing some odd jobs but it's not a battle anime. though occasionally, there is some of the arc like the Benizakura, Yoshiwara in Flames and Red Spider arc that involves a lot of amazing battle scene(the protagonist Sakata Gintoki, is a samurai after all so no surprise with the battle action scene).

anyway basically, Gintama is a slapstick comedy anime that include some parodies of manga/anime like One Piece, Dragon Ball, Gundam and many others. also you will witness some dirty boner jokes in Gintama and some nude scene with mosaic lol. another thing worth mentioning is Gintama have lots of supporting characters that will 'fire' up the show if you like comedy and enjoy spoofs of other popular anime then i will no doubt recommend you to watch Gintama if not you better look elsewhere.

i can't help you with Hitman Reborn. never watch it before.