That all depends. Are you wanting a reseller, for the sake of running a business? Some people buy them just to host a massive amount of sites. Which catagory are you? Space is important because, you need to have enough, to host the sites, but not too much cause you dont want to pay for something your not using. Server specs are inportant, but as long as they are decent, 2.0 cpu, 1gb ram) then you will be fine there. The most important is support, you need to be able to reach someone on behalf of your clients if anything goes wrong. The more ways to reach a host the better imo. AIM, MSN, ICQ, Phone, Email, Text Msg, on Cell phones, I find these are all worth while to my clients, so if you find a host that offers those, or a good number of them, its a decent deal.
HTH
-Steve
