dpixel :
Thanks for all the great info. The Crucial MX 100 looks like a reasonable price. I guess my biggest concern is quality. I don't want it breaking down after a few years. Are there ones to avoid? Do they run hot at all?
Ah dammit, just wrote you a long reply and then managed to trash it... I hate it when I do that.
Trying again:
All SSDs to have a endurance limit. Each NAND cell can only be written to a certain number of times before it can no longer hold a charge and is, effectively, worn out. Much has been made of this issue but it's massively overblown. Sure, if you have some unusual write intensive use case (like hosting a write intensive database), you'll need to be much more careful in selecting an SSD, but for the vast, vast majority of users it's simply not an issue. Check out Anandtech's analysis of the 840 EVO (which is one of the lowest-endurance drives on the market) - there's really nothing to worry about with write-endurance:
http://www.anandtech.com/show/7173/samsung-ssd-840-evo-review-120gb-250gb-500gb-750gb-1tb-models-tested/3
The bigger issue with SSDs in the past has been dodgy firmware which has bricked drives. These issue plagued the once popular OCZ SSDs, and really damaged the reputation of SSDs in general. Still though, it's almost destroyed OCZ as an SSD company, so I'm hoping that the other company around noticed and now pay much more attention to testing. Grab a good brand and you're as safe as any of us.
SSDs in theory are much more robust than HDDs, they have no moving parts and produce less heat. Of course, whatever storage you use (SSD, HDD, flash drives) all important data should be backed up and a good brand is never a substitute for a good backup. As I say, grab a good brand (and Crucial have a good reputation) and you're as safe as any of us.
That MX100 is a good choice. Plus, they're on special at Newegg at the moment. Grab one, they're the best upgrade you can make for a PC IMHO.