Well as xmas time is coming I'm finally planning on upgrading to an SSD as a boot drive. I've been using HDD as boot and generally it's been okay, but I've heard that SSD upgrade is one of the best upgrades you can get for your PC. So that's it recommend me an SSD. Capacity side of things I don't know. I would probably store my music, games, movies on HDD, but general programs would be stored on an SSD.
I would suggest a 128 GB SSD a 64 GB would work great but it would only be big enough for the OS and a handful of programs and storage would quickly run out. A 128 GB would be perfect for the OS, programs, and maybe 1 or 2 small games. As for the brand there are some cheap ones like the Kingston hyper x, or the Plextor M5 pro, and even the Samsung 840 and 840 evo.