In all honesty, mid to high-dose Seroquel. Sometimes I have a love-hate relationship with it, but it does work for me. Some don't like the side effects, but they are manageable enough for me. I thought it was just a mood stabilizer/AP, but when I lowered the Seroquel, the anxiety came back really bad. When I went back up on it, it made me realize just how much it was helping me with anxiety/panic as well. I won't budge from any dose lower than 300-400 mg from now on. I feel it "boosts" the effectiveness of klonopin too, which I find to help with anxiety and panic, and I usually don't feel the need to take too much of it.

Lorazepam worked pretty well and is a good PRN. Xanax works very well as far as fast relief, but it's too short-acting by itself (and it's addictive potential could be problematic for some people, but that's with every benzo). I like how klonopin lasts pretty long though. Gabapentin is helpful too.