Are you thinking of building a new desktop (or laptop, with more than one HDD slot) rig? Not sure what size SSD to get? I highly recommend an SSD in your budget. It's the single biggest boost to performance you can get these days. I can vouch for 64GB being enough, as long as you have extra 1TB+ platters in the system. Here's why: It takes 5 minutes to set up Program Files etc directories on the slower HDD, change default location of your libraries (Music/Docs/etc). You're now set up. When installing stuff, you either leave it as default C:\Program Files\Blah path to install on SSD, or just change the first letter to your HDD to have in install on the slow drive. No registry hacks, nothing to corrupt, all fine and a 2 second modification when installing. 64GB is enough to have everything on Win7 turned on (apart from Hibernation), such as Indexing, System Restore, etc. You can install the OS, Office Suite, two full Adobe Master Collections, as many browsers as you want, Steam, chat clients, etc. Everything (unless you're a pro user - read: work) will fit, with at least 10% free space remaining for garbage collection and wear levelling. It depends how rich you are, but games honestly don't get that much of a boost. You load a game, you play it for a couple hours, you close it down. You're not opening/closing games every 2 minutes, so that 2-20 second SSD advantage doesn't add up to much. Considering Steam libraries these days, a typical person would need an ADDITIONAL 500GB SSD in their system just for games - 500GB for OS/programs/games is sometimes not enough. I have 1TB WD Black on SATA2 and I still load games very fast. Granted, if you only have 1-3 games you regularly play, coupled with the more economical cost of a 120GB+ SSD, it may be a wise decision to get this and install said games on the main drive, with other games on your HDD. Worth mentioning one more time - the $/GB is better when purchasing 120GB SSD, and gets better the higher you go. I have a $3000 rig, $1400 monitor, and another $1400 SteamBox. Not to be a douche, but Im saying this because this is in the realm of "dude has money to spend on PC". I am here, telling you that I'm still fine with my 64GB SSD on my main gaming rig and there's no need to upgrade until entire rig dies. My SteamBox has a 500GB due to: cost efficiency, silence, and because I don't have my full games library on it. _____ To finalise: if you have a desktop PC and have other 1TB+ platters, and you're on a pretty tight budget, 64GB will suffice no problem. If you can't control yourself (e.g. when installing) or you're forgetful, maybe it's worth spending that little bit extra to get a 120GB one (if your budget is loose enough to fit it).