I proffer to beta for things that I know a lot about. My strongest topic would be Harry Potter. For Harry Potter I am picky about pairings. I will NOT do HP/GW, or RW/HG. I know that's weird because they are the traditional characters but I never felt like they should have been. I won't do any pairings that involve Severus, Ginny, or Wormtail. I used to love HP/HG, but not so much anymore. I will try though if someone would like me to beta for that topic. My favorites are LE/JP, DM/HP, and HG/DM. I will do any pairing that involves Sirius (if he is in character enough). I LOVE Sirius Black. I would even do a SS/SB story if it involved Sirius because I think he is that much of an enjoyable character. I would also do well with a Twilight fanfiction.
For twilight my standards are pretty basic. I won't do any stories that are vampire/wolf. Not even Renesmee/Jacob. I don't really like the wolves, but I am more than happy to do the Vampire stories. I'm not really picky about the preference here but I'm not really into stories where they're all human, I would like the vampires to actually be vampires. But I'm completely fine with vampire/human.
I can do Grey's Anatomy.
I will not do any stories with Meridith and Derek with other people. I strictly believe they should be together. End of story. I won't do anything with Addison, Izzy, "Little Grey", or Christina. I love three out of four of those characters but I'm not really a fan of their fan fiction.
Ugly Betty.
I love Ugly Betty and I would be very capable of beta stories in that category.
I would love stories about Mark or Justin, they are my favorites.
I won't do stories with Betty, or Amanda. Sorry.
I can do pretty much any show on the family channel. It's sad but I can.
I can do both of the Suit Life shows, but I proffer the Suit Life on Deck.
I'm very capable of Hannah Montana, but I will not do Liley. Not gonna happy. I have a huge preference for Mikiley though.
I would do Wizards of Waverly place without trouble. Alex is my favorite. I won't do any stories with Harper. She creeps me out.
And I can do Zoey 101 but I will only do Zoey/Chase, Quin/Logan, Micheal/Vanessa. Yes the original pairings, I like them the way they are.
I'm not the biggest fan, but I can do The Latest Buzz. But the only pairing that I think I could really do for it would be Rebecca and Noah.
I would be thrilled to beta for a Life With Derek story, only Casey x Derek, though.
If there are any Disney shows that I haven't mentioned, that you are wondering about, feel free to ask.