Avenue Q!!!! DEFINTELY worth missing Rent or the Producers. Both shows are far overrated, in my opinion. Avenue Q is smart and incredibly entertaining.
I'd also invest in the shows that will be opening around then -- mainly Wicked.
*I* will be seeing Never Gonna Dance because its based on my favorite Fred/Ginger movie, but I have a feeling it won't be as strong a cast as previous musicals listed. It's a light hearted romantic comedy put to Jerome Kern's music, though... if that piques your interest. Doesn't sound like something you described.
The new Nine cast should be something to see. I will certainly be revisiting. I really enjoyed the production with the original cast. That should also be something you look into.
Don't automatically go to the overrated shows -- you could be missing out on some great new stuff! :)
"You! You are the worst thing to happen to musical theatre since Andrew Lloyd Webber! And you, well, I just plain don't like you."
~Stewart Gilligan Griffin