I really like Text Link Ads, although one of my 2 sites was rejected too.
They are very picky about which sites they accept. Read
this interview with the founder of TLA, in which he explains the factors of their algorithm.
The reason I like TLA is because my blog is doing very good with it! Currently displaying 4 links, making me at least $44 for november. That's probably about 10 times more than what my blog could make from adsense!
Btw, there are other ad brokers, like
Performancing, which are not so picky...