I've been track riding for 3 years now. The tracks I've been on are:
Pocono(East, North, & FUSA)
Summit Point, WV(Shenandoah & Main)
New Jersey Motorsports Park(Thunderbolt)
A lot of people complain about Pocono because of piss poor track conditions(lots of ripples, runoff is treaherous, and transition patches are rough) and they don't usually like to cater to bike clubs. However, I can't complain much about it because it's my home track(only 30-40 minutes from where I live).
I ran Shenandoah twice in '08. First time I did it I hated it in the morning but fell in love with it by the afternoon...so much that I made my way back there 2 weeks later...and crashed, but still loved it.
Thunderbolt @ NJMP is really nice( very fast & technical) probably because it's a brand new facility. I unfortunately made a run there while I was sick and ended up puking after almost every session so I didn't really get to enjoy it to the fullest. This year I'm really looking forward to hitting it again, only under better health conditions.
This year I'm hoping to add a couple more tracks to the list including BeaveRun, NJMP (Lightning course), Summit Point (Jefferson) and maybe even VIR.
Sorry for carrying on but when I hear anyone mention trackdays or racing it gets my blood pumping again so I love to hear about other people's experience and share a few of my own.
To sum it up I don't have a favorite track because I'd gladly take any one of them over a day at work anytime.