Actor Panel Experiences:
I'll state right now I got spoiled on local AWESOME Star Trek cons as a kid (which aren't being ran anymore

One at the local con here, and it was lots of fun times, guy named Kyle Hebert, he knew how to work a crowd, and yay for Perry The Platypus! It was massively entertaining times.

The only other one I remember going to (not really by choice) was that Vic Mignogna guy. It was only because AWA was running late on showing the AMV winners, and he wouldn't stop talking (and he had to show his amv as well! he had a friend make an amv to some song he sang). It wasn't very fun at all. He seemed fairly self absorbed and the fangirls were just wanting to hug him, give him presents, and asking him to do "voices". (Not to mention I'm not a fan of his acting, he's more "miss" for me than "hit", he usually sounds really fake.)
I suppose if the option to go to an actor panel came up, it would depend on the actor. I'm sure some of them are more interesting than others. Not to mention, some of them I like their work more than others.
Cosplay:
The Masquerade interests me if there are some good skits. The last one I went to at our local con had mostly not very good skits. Also, a lot of people just came out and twirled around to show off their costume, no skit at all. I think there should be a separate contest just to show off costume work. So the last one I went to was pretty disappointing, however with a show like that it's a take what you can get. Not to mention the local con (no matter how big they like to pretend to be) is pretty darn small. I don't really see myself lining up for a cosplay event though.
I also enjoy taking photos of cosplayers, I prefer the ninja photography style because I'm usually fairly embarrassed to ask anyone to pose for me. I really wouldn't mind doing an outdoor photoshoot or something, but I don't know many cosplayers so I feel fairly shy around them.
AMVs:
AWA and ACEN are the "editor cons" I've been to, and AWA was the one I had the most fun at. However the one time I went to ACEN was the year of the 10+ hour reg line of hell


RPG/Video Game Room Stuff:
It seems most of the RPG stuff I've ever seen was complete fail. I'm not really into RPG stuff. As for game rooms, the ones here have games I've never seen or heard of.. Para Para is fun, and I don't have DDR myself. The local con also holds Pokemon TCG tournaments (unofficial I believe), I don't know how to play, but they are still kind of interesting to watch... maybe?
Watching Anime:
It depends on the show I think. Not knowing anything about FF7 watching Advent Children with a crowd wasn't much fun, as it just proved the movie to be one huge fangasm. Watching episodes of stuff that's recently licensed can be nice though so I can have an idea of what I'd like to purchase in the near future.
Other:
For the most part I go to cons to watch AMVs see costumes and the biggest reason: to hang out with friends. I've been going to the local cons here so my nieces and nephews can get a taste of the con scene to see if they like it, and they seem mostly interested in entering the amv contests and playing video games.