Intel X25-M . Boots are good (but keep in mind your motherboard plays a big role in this too so YMMV), programs will open faster than before as well. But don't expect a ridiculous change in speeds. A lot of folks are disappointed when they get a SSD and it's not 1000s of times faster like they might expect.
Most of my workstations have Velociraptors as boot drives, one's got a top of the line SSD. Only a slight difference in program launch speeds in favor of the SSD and it's so minor it might just be wishful thinking