i meant series length, most eps are around 20mins you do have some series that have 40 min eps.. like hellsing.
if you want to watch something long... you can tackle One Piece, its made by the same studio as Dragon Ball z, but its very long...
the new stuff isn't that great but it has a lot of good arcs in the series.
also try something like steins gate, code geass, Fate/Stay night has a few seasons very good series
those are few to check out, theirs a lot more and also depends in what you are into.
if you want to browse anime that i have watched go to my list,
http://myanimelist.net/animelist/Kenpachi15 all of it is there, it will also give you the summary of each anime
happy watching