lucky.you already finished rosario vampire.lol.Well here are some that I own that I enjoy.
D. Gray Man.A nice adventure type series with exorcists.lot of action.and not exorcists like the ones from hollywood.cool ones.
Nora the Last Chronicle of Devildom.Good action series.A little similiar to inuyasha,but in a good way.
Hikaru No Go.From the same people whomade death note.
Bakuman.a relatively new series,also from Ohba and Obata.
Buso Renkin.a series by nobuhiro watsuki.very good.
If youre fillinf a little ecchi,Battle Vixens.Tons of Fan service and good fight scenes.
Katekyo HItman Reborn.A funny series with action. sorta young age in the early volumes,but it gets way better at volume 8.more action.
These are just some that I like.Read them and enjoy.^^