I'd say you can't go wrong with the Rondo Red @ £300. Listened to it on a Project Xperience, and was really impressed with it. Nicely neutral without being anti-septic, tracked superbly, very enjoyable.
Cartridges come in many flavours, but the Ortofon is a thoroughly safe place to start, with no unexpected nasties to catch the unwary.
Other options might be Sumiko Blue Point Special (£250), which a lot of dealers seem to use in demos, which is a good sign. But it's also notoriously delicate, and there always seem to be broken ones for sale on
eBay. I want to own one at some stage, but wouldn't want to rely on it as my only cartridge.
Denon's DL103 R has just become available in the UK, at around £200. I've never heard one, but have one on order. Some people swear it's the best thing since sliced bread, and I've seen one guy say he prefers it to a Benz model at three times the price. But for every fan, there's someone else who hates it, so a slightly risky purchase.
Conclusion: Buy the Ortofon!