Some I have had experience with ...
Suunto Favor - my first computer. PRO - easy to use, easy to understand, inexpensive. CON - doesn't do nitrox, battery not user-replaceable (expensive to replace)
Oceanic Versa Pro - I owned two of these, both experienced failures. The first one failed to shut off after a dive, telling me I was at 7 fsw while I was driving on I-5 after the dive. By the time I got it back to the LDS it told me I was several hours into deco. The second one failed recently, at a dive park that max'es at 40 fsw. During the dive it read that I was at 161 fsw, and then went into permanent failure mode. It's still sitting at home, useless and broken. I won't own another Oceanic computer. This type of failure is simply unacceptable.
Aeris Atmos II - another Pelagic made product, very similar to the Versa Pro. One of my regular dive buddies has gone through eight of these over a period of about a year. On a recent dive our depths and times were so far apart from each other you wouldn't even think we were on the same dive ... by the end of the dive her computer showed 24 minutes more than mine, even though we descended and ascended together. I know a few divers who own these ... and to a person they are so untrustworthy that they all carry backup computers.
Dacor Darwin - ironically, the backup computer of choice for the majority of the Aeris Atmos II owners. Relatively inexpensive, user-replaceable battery, and simple to use.
Suunto Vytec - the computer I purchased to replace my Oceanic Versa Pro. I've only used it for a half-dozen dives, and I'm still figuring out how to use it. The first dive, it failed to come on when I decended ... and I was with students, which is worrisome for someone who doesn't have backup instruments. About 2 minutes into the dive, the computer went into dive mode ... but it ended the dive while we were at about 12 fsw, which is also worrisome. It turns out this was due to a weak battery (in a brand new computer). Once I changed the battery it performed fine. One thing I do not like about this computer is that the manual is just awful ... you have to read each section several times to figure it out, and it's more a list of user features than a document that explains how to actually do stuff with the computer. If you're a geek, this is the computer for you ... it'll probably tell you what you had for breakfast if you can figure out how to select the proper menu. But you won't even learn how to access your log by reading the manual.
You should ask OE2X about the Uwatec Aladin ... he's not terribly happy with the one he owns.
Some general comments ... If you're looking for a computer with a very conservative algorithm, look at Suunto or Uwatec. If you're looking for a less-conservative computer (i.e. more allowable bottom time before telling you you're approaching deco limits), look at the Pelagics (Aeris or Oceanic).
Whatever you do, make sure you buy your computer from an authorized dealer and fill out the warranty card.
... Bob (Grateful Diver)