Well, I?m currently reading Part 3 of JoJo?s Bizarre Adventure online, and as far as I?ve heard, they do have an English release of it (only Part 3, though) on Viz that you pick up on Amazon (although, like, half of them are ridiculously expensive, over £100; I?ve opted to just buy the first one and read the rest online). Part 3?s good (although I?m feeling a bit impatient waiting for Jotaro and co. to fight the Big Bad already), and if it?s anything like the previous two parts (of which I watched the anime?s adaptation), it should become great. It is an ongoing 108-volume series, though, with eight story arcs, so if you end up deciding to follow up, you?re gonna need a lot of time, patience, and Japanese passions, if you don?t want to read online (which I understand; I hate it too, and only put up with it for hentai and manga I really want to read but don?t have the money for at the time).
There?s also Fullmetal Alchemist, which is, IMO, the best Shounen manga ever and its themes and characterisation actually transcends the clichés that tend to bog down the genre. It was adapted into two animes; you can watch either one or one after the other, although I prefer the second one, Brotherhood (which was adapted directly off the anime, minus a few parts cut out that was already adapted in the previous anime, which had minor filler and veered off into its own original story).
Oh, and you could check out Wandering Son too, a slice-of-life manga predominantly about two teenagers? issues with gender identity, that also has an anime adaptation. And I?ve heard nothing but good things about the works of Osamu Tezuka, dubbed the ?Grandfather of Modern Manga?. I still have to check out some of his works, like Black Jack and Faust.