You don't have any information in your profile that would help us refine our advice, but here are a few things I've learned to look at when considering a computer:
First off, how's your eyesight? For those of us in the older age brackets, reading small displays in limited light can be a real problem. This is far less of a worry if you only dive the tropics, with high ambient light (but even there, can surface as an issue on night dives). Small computers, like the Gekko and Mosquito, can pose problems with small displays.
Second, do you want air integration? If you do, in the price range you're considering, you're looking at a console unit, which makes it easier to get a large display. But I found dragging a console up constantly to check my depth was a nuisance. Depth is something I want to reference constantly through a dive, so I like my depth gauge on my wrist. But adding air integration to a wrist computer involves an expensive transmitter and some potential issues with getting the transmitter and wrist unit to sync.
Third, do you have regular dive buddies, and if so, what do THEY dive? Different computers use different algorithms to calculate no deco time, and the results can vary quite a bit. If your buddies are using fairly liberal computers and you buy a conservative one, they may be irritated at having their dive time cut by your appropriate desire to remain with no-deco limits. (On the other hand, you may deliberately CHOOSE a conservative computer for your own desire to be conservative about dive time.)
Fourth (and this may seem trivial, but for me, it's not) if you DO want a wrist computer, how do you want it to attach to you? Most computers come with some kind of strap that buckles or Velcroes on. If you are using a 3 mil suit (or shorty, or no suit) for tropical diving, this may do fine. If you are diving cold water, whatever you wear is going to compress with depth, and a buckled or velcroed strap is going to get loose, sometimes permitting the loss of the unit. Deep Sea Supply makes boots for a variety of computers, which permit the use of an elastic bungie as a securing strap -- one which will adjust automatically as your exposure protection changes through the dive. To me, if a unit doesn't fit in a Tobin boot, I'm not going to buy it!
So -- no advice, but a few questions to consider as you think about what to buy.