For a laptop, this one: Intel X25-V Value SATA SSD 40GB MLC SSDSA2MP040G2R5 34nM.
If you have a desktop computer and you want performance, you must go for a 64Gb one. That's why the performance of the 32Gbs ones is very bad. A H.D. like the Samsung Spinpoint F3 HD103SJ 1TB SATA 3Gb/s 32MB-cache is much better.
A good 64Gb SSD is the Patriot Torqx 64: