the cateye micro wireless has treated me really well, had it for a few years and i actually have 3 of them. one for each bike that i care to record my data on, not because i've had problems with any of them.
it kind of depends on what features you're looking for and how much you'd like to spend. i kknow cateye and a couple others make ones with HRM's built in, others have Cadence. What features are you looking for?
kyle