Suunto seem to have the market at the moment. They can be very conservative at times but that is not such a bad thing. Their RGBM is good stuff. They also punish you if you don't take the 3 minute safety stop.
http://www.suunto.com/suunto/main/article_1column.jsp?search=search
The Vyper is excellent, a design classic, and good value.
The Stinger is a Vyper in a watch and has become the instructor's favourite.
The D9 is a Stinger with more bells and whistles. A small object of desire.
If you want to have the best then you need a VR3 with a colour display.
http://www.vr3.co.uk/vr3/main.php?content=intro
The world's best dive computer by far.
You can watch the loading in each compartment in real time.
Watch a graph of your dive profile.
Switch between 10 gasses on one dive.
Input PPO2 with a rebreather automaticaly in real time.
Reprogramme everything whilst underwater.
Use VPM algorithm (next year)
etc etc
It is constantly upgradeable and grows with you.