I was originally going to say location, but then I realized that of the 14 tournaments I played this year, I played a few outside of a 200 mile radius...
For me, it has to be PDGA sanctioned. The only time that I play when it isn't PDGA sanctioned is when it is a fundraiser for a local course.
The more rounds the better in my opinion, except for one round days. Although it is nice to get out early on Sunday and get home early, if I have to travel any distance to get to the tournament and have to pay for lodging, I hate having to spend a night to play just one more round. If the tournament is local, then it obviously doesn't bother me.
If the tournament is a two day tournament, then there has to be cheap lodging near. It is awesome to have a tournament sponsored campsite nearby as all the disc golfers can mingle there after the rounds for the day. I also like player's parties the night in between tournament days to add to the camaraderie and have something to do if I have traveled some distance to get there and know nothing of the area.
I don't care about players packs. I have plenty of discs, towels, and minis. Already have a nice umbrella and stool. And regular shirts don't fit me well enough, so I prefer lower entry fees.
As an AM, I really prefer a smaller entry fee, but am fine with a larger one if the payout is reasonable. Although I have more than enough discs, I just want to feel like it was worth my money.
I almost forgot the size of the field is really important to me. I find playing in small tournaments boring. My ideal tournament is a 4 round tournament with 20+ people in my division to really get the competitive juices flowing.