finding a good host is more than just price.
find out who the big guys are using, check the pricing for the hardware and BW you need.
run a traceroute to the host from multiple places in the world (very important) and time the composite results. some hosts just have more connectivity than others, and will actually be able to get to places other hosts can't reach.
http://www.tracert.com/cgi-bin/trace.pl
i.e. if most of your traffic (sales) are coming from USA and europe a host in eastern usa may be a good choice as it will minimize hops.
be concerned if your host harbors email spammers, some of their ip addresses may be blocked and you might be blocked through no fault of your own.
if two hosts are similar it will boil down to tech support, both speed in handling issues, or competence. (assuming you are on a managed server)
that said, i can recommend 2 hosts i've had good experience with:
hahahahahaha
webair (so far the best i've ever had)