Adding to the above, there's also the pantech burst unlocked
No good for t-mobile, EDGE only, it doesn't do HSPA+ on t-mobiles AWS frequencies, otherwise it's a good phone especially for AT&T. I suppose if you are happy with 200kps it's OK on t-mobile, but I would rather have the 9 mps I can get on t-mobile hspa+ where I live.
The exhibit II should be at $100 unlocked, it's not a bad phone but it's not worth more than that in my mind. t-mobile choices sort of suck though because of their AWS 1700/2100 hspa+