As always, I'll go with my sure bet favorite shounen series: Hunter X Hunter. Around 72 episodes TV series, and about 3 OVA series as direct sequels. Still hoping for a new OVA series to come around when the mangaka decides to finish the current arc in the manga.

The Read or Die series is pretty good too. Watch the 3 episode OVA first then the TV series released by AonE. The TV series is called R.O.D. TV, rather than Read or Die.

I don't tend to watch many anime movies, so can't really recommend any. Maybe the OVA Hoshi no Koe and the movie Beyond the Clouds, The Promised Place, but I'll bet you've already seen those.