The Intel SSDs are good; they top out at 160GB and they're not as fast as some of the newer drives - but their track record is nearly flawless. It's what I have, but I ordered one the minute it was posted on Newegg last year. Some of the newer Sandforce-based drives are supposed to be good, though you'll want to pick one from a reliable manufacturer and with a stable firmware. If you have a Mac, OWC[1] is a good choice, as I believe they have firmware that garbage-collects HFS+, which helps to keep the SSD as fast as possible. I also think OCZ is good, but check reviews to make sure people aren't having too many problems.
You can also get a brackets that replaces your optical drive, and allows you to fit a 2.5" HDD. I have one in my 17" non-unibody MBP, and it's really the best of both worlds - I keep OS X, my working files and apps on the SSD, along with my main Windows XP web testing VM. My iTunes library, media, and games stay on the HDD, along with a Boot Camped copy of Windows 7 (though it's a pain to get the installer to run without an internal optical drive). I keep a cheap Samsung bus-powered DVD burner in my bag, but in reality I rarely need it. I think OWC sells a bracket for Macs, but if you can figure out exactly which bracket you need, a site called newmodeus.com sells them for almost every laptop ever made for considerably less.
I really do believe my SSD is the best upgrade I've ever spent money on; no computer I use from now on will be without one. It's not so much that the computer is faster; it's more the feeling that the computer does not grind to a halt or slow down, no matter what's going on. (I may have compared my computer to the Terminator amongst friends once or twice… it just doesn't slow down.)
You can also get a brackets that replaces your optical drive, and allows you to fit a 2.5" HDD. I have one in my 17" non-unibody MBP, and it's really the best of both worlds - I keep OS X, my working files and apps on the SSD, along with my main Windows XP web testing VM. My iTunes library, media, and games stay on the HDD, along with a Boot Camped copy of Windows 7 (though it's a pain to get the installer to run without an internal optical drive). I keep a cheap Samsung bus-powered DVD burner in my bag, but in reality I rarely need it. I think OWC sells a bracket for Macs, but if you can figure out exactly which bracket you need, a site called newmodeus.com sells them for almost every laptop ever made for considerably less.
I really do believe my SSD is the best upgrade I've ever spent money on; no computer I use from now on will be without one. It's not so much that the computer is faster; it's more the feeling that the computer does not grind to a halt or slow down, no matter what's going on. (I may have compared my computer to the Terminator amongst friends once or twice… it just doesn't slow down.)
1: macsales.com