I've owned a CycloDS for over a year now and I've never had any problems with it. The support for it is excellent and the firmware is regularly updated. I don't really know if there are any better products out there but I've been very satisfied with it, and I have no plans to replace it.
I've got an Acekard 2i and have problems with the DS not reading it occasionally, and if it gets bumped hard enough while playing the DS will freeze. The upside though is it cost like $12 on dealextreme. It doesn't have those little plastic dividers around each of the contacts so I think that's what's to blame.
Just picked up a CycloDS on DealExtreme, we'll see how well it works when it arrives next week. Thanks for the recs, guys!