I have used four different brands of SSD. Performance in actual use has not been noticeably different between and among them, at least not to me.
Most people are suggesting Sandforce controller drives; these have excellent performance and the latest features like TRIM support and background garbage collection. One glitch worth noting though, I have seen myself and read online that these controllers may have trouble waking up from a sleep or hibernation state. A firmware update may [soon] be available to address this, but having to upgrade something new out of the box seems unreasonable to me; I have chosen to prevent the systems that use them (one of mine and my wife's) from going to sleep or hibernating, and have no problems.
Edit: OTOH, the JMicron controllers are widely considered to be substandard to the point of being "junk" to some. The cheapest drives, like Kingston, use them. Mine have been Sandforce and Intel (also good), so I can't comment from personal experience; I don't think I'd buy one though.
My vote is for Intel brand. Been running the 80GB X-25M G2 in my rig for the past 2 years now. Its been great. I haven't noticed any slow-down in performance. HDD benchmarks still show roughly the same read/write performance today as it did the day I installed it. The newer, 3rd gen, 320 and 510 series from Intel perform even better, but at a higher price.