If you're buying from OCUK then £169 for the Crucial M225. Otherwise the Samsung or Corsair P (Samsung) drives are a bit cheaper, but don't have TRIM, a shorter warranty and no firmware updates.
I can't really recommend any of the cheaper drives in stock, either using the JMicron or too expensive for the OCZ drives when you look at the capacity of them.
If you're prepared to shop around the Intel X25MG2 at £159.99 is an absolute no-brainer.