There's a big fat EA racing sale going on over on Steam, and Hot Pursuit is probably the pick of the bunch. Of course, that all changes if you somehow don't own Burnout: Paradise, because The Ultimate Box is only £1.24. If you're only just dipping your toes into this sort of thing, definitely plump for Paradise.
Or you could buy the whole EA Racing Pack (Need for Speed Undercover, Burnout Paradise: The Ultimate Box, Need for Speed: Shift, Need For Speed: Hot Pursuit, Shift 2 Unleashed) for £13.74.
In Need For Speed: Undercover, you'll be playing a cop, who surprise surprise, has to go undercover in order to bring down a criminal syndicate. You can expect to enter into a few races and take on some risky jobs in order to establish your cover and when you're not making a nuisance of yourself you'll have time to explore the open world environment. The £11 price tag at HMV'll make you a saving of over £1.50 on the next best offer coming in from DVD.co.uk.
As part of their week of EA promotions, Steam have slashed Need For Speed: Undercover down to a pocket money price tag (that'll save you a fair few quid compared to the few retailers who are still in stock). However, even the staunchest NFS fans have to admit that it wasn't the series' finest hour. The open world setting is boring, bland and pointless, and the difficulty level is laughably easy. Not to mention the terrible live action cutscenes. Still, it is cheap, and the graphics have held up fairly well. It's your call.