I think you need to pick a network, not a phone. All three phones are similar, but each is for a different network.
810 - Tmobile
820 - AT&T
822 - Verizon
I personally think that the 810 looks the best, and has better features than the 820, and basically the same as the 822. I also think Tmobile is the best company, just because they're by far the cheapest. I also get service everywhere I go (work, school, home), so the coverage is as good as the others. Go with the 810 and Tmobile, that's what I'm doing.