Avenue Q is already a hot ticket. And recommended. I think it's a bit of a light story, but it's clever and well crafted, and the score is both original and fun.
Sweet Charity hasn't started previews yet, so it still looks promising.

It has been successful in the past, and it's a good score.
All Shook Up and Good Vibrations have been receiving very mixed, if not negative, word-of-mouth. (I think the word is a bit worse on GV than ASU, but that's my perception.) They could/should be fun, but I'm not sure how well they succeed. They don't particularly appeal to me (from what I've seen in the Macy's Thanksgiving Day Parade and rehearsal clips).
Little Women has also received mixed word (I think the official opening is very soon). The score hasn't impressed very many, but if you know and like the book, I think it might work on that level. Sutton Foster is supposed to be very good, and Maureen McGovern is getting some nice comments, too.
I would think that if you want to get tickets for Avenue Q, and maybe even for Sweet Charity, you'd want to buy in advance. I'm not sure if the others will be that difficult to get.