Well, I haven't played many, but if you're looking for a medium-sized (45-mins to 1 1/2-hours) fun adventure map, I would play either Caves of the Ancient or Eronev Mansion Adventure.
If you want fun PvP matches, Rush (last time I heard, Rush was bugged) seems fun, along with Knights of Kingdomia (which I played, but didn't seem to work properly). Grifball's insanely fun, but insanely hard as you can't tell who has the Grifball.
Diversity is one of the greatest maps I've every played, everything is top notch. Also, as for Parkour, you should do TPC Parkour, but there's no way you'll finish all of it...
