You want to look at SUSTAINED read and write speeds when shopping for an SSD. The speeds advertised are typically burst speeds, but the SUSTAINED speed is what really matters.
I don’t want this to look like a product review, but I want to share my experience. I have had several OCZ Vertex SSDs and I can tell you they work GREAT… when they work. Of the three OCZ 120 GB Vertex drives I purchased about a year and a half ago all three have failed, and some of their replacements have failed. OCZ has been good about replacing the drives but the kind of repeated failure I was seeing is not acceptable. OCZ recently upgraded all three of my drives to the Vertex 2 drives and (so far) they are working well.
With that in mind the other number(s) you want to look at are MTBF and/or MTTF. I personally do not think OCZs MTBF number of 1.5 million hours for the Vertex SSD is accurate (since they were failing roughly every 3 months). Their Vertex 2 drives list a MTBF number of 2 million hours (hopefully for my case this is accurate).
While OCZ has taken care of me if I had it to do over again I would probably pay a bit extra and go with the Intel drives. If you look on Newegg there are maybe five people who have said their SSD failed in the Intel reviews, but nearly every other person said their OCZ drive failed. With that said it you can see that failure is possible no matter what drive you get, so make sure you get one with a good warranty (nothing less than 3 years for me).
Also read up on the newest controllers. When SSDs first came out J-Micron was the controller to have, but now you also have Indilinx Barefoot, Samsung, Sanforce, and Intel to pick from. My reading suggests that SSDs with either the Sanforce or Intel controllers are currently the way to go. A website called Benchmarkreviews gives excellent reviews of the newest SSDs and compares them to other SSDs, I suggest you do some reading there before you make your final decision.