I'd suggest a Rover, there are many different models with that spec and budget. They've got a fairly bad reputation but from my experience (I've had several) they're actually fine.
If you want a small car the Rover 200/25 is a huge bargin, but that's a hatchback. Perhaps the Rover 400 / 45 would be ok? You can get a really REALLY well specced 2000 - 2003 model for 2 - 3k and it comes as a saloon.
For something bigger, if you want a larger car, try a Rover 600. Avoid the 1.8 as it's a bit underpowered but the 2.0 petrol or 2.0 diesel offers a good mix of economy and performance and I picked one up recently for 1.5k with aircon, cd changer, power steering and as its a diesel great reliability and 40+mpg.
I'm a huge fan of Rover so I'm a bit biased but I'd recommend you look into it - try car-survey.org which offers owners reviews rather than industry opinions.
Otherwise you could look at a fiesta, corsa, older style mondeo or vectra or several other makes. www.parkers.co.uk offers price guides and advice.