I would get a cheap 60-120gb SSD if I wanted to put it in my PS3. Since the PS3 bottlenecks it anyways, there’s no point trying to get the “best performing” SSDs with fastest read speeds and all that.
For the “specialist” gamer, meaning one that doesn’t necessarily buy tons and tons of games every year, but one that has a select favorite set of games and plays them for years at a time. For example, a fighting game player, gran turismo player, SHMUP player.
As for the “hardcore” gamer that buys nearly every big release under the sun, I wouldn’t suggest an SSD because of the shear amount of instal files, DLC, etc they would have to go through. Where a small capacity SSD wouldn’t be sufficient.
The early model PS3s came with 60gb, 20gb, 40gb, 80gb HDDs. And if someone wanted to, they could just manage their game installs to the point where 60gb would be enough. If you installed GTA4 with its 5gb file in 2008, I’m sure you would have deleted the instal file already in 2012 if you haven’t been playing the game for 4yrs, and needed more space in your PS3.
Sometimes you can find a 60gb SSD for $50. Which isn’t much for a nice little performance boost. Especially if the game takes advantage of the speed well. Just remember all games perform differently with an SSD. Maybe someone could test out SF4 and other fighting games with SSD loading times. I know for a fact GT5 has a large benefit with SSD loading, since the loading times are really long.
edit: Here’s a nice vid that shows the difference with GT5