If its in your budget then I would pick up a Samsung evo they've been seen around $150 pretty frequently.
Don't forget to get a 2.5in to 3.5 in bracket/adapter for it so it will fit in your drive bay!
Important: Before installing Windows 7/8.1 on the SSD, be sure you go into your motherboards BIOS and change the SATA controller setting from IDE to AHCI. This will enable a number of additional features on the SSD (trim, etc) and provide performance increases.