OCZ's Vertex 3 240 GB flagship offers outstanding drive performance on the new SATA 6 Gbps interface. In terms of raw speed it is only beat by the more expensive Intel 510 Series SSD. OCZ's next smaller model the Agility 3 is about 8% behind in performance, but also clocks in at a much more competitive $400, resulting in a better price/performance ratio. If money is of secondary importance to you and you want a fast drive, then the OCZ Vertex 3 is a great choice. Crucial's M4 SSD has recently seen a firmware update which promises significant performance updates and could result in that drive becoming a direct competitor to the Vertex 3, too.
For optimum performance it is recommended to pair modern SATA 6 Gbps SSDs, like the Vertex 3, with the matching interface on the motherboard side, otherwise you'd see a real-life performance difference of around 15% which it not negligible but also not as big as what you would expect from double raw interface bandwidth.