I bought one of these about 6 weeks ago:
http://direct.tesco.com/q/R.212-7205.aspx
Proving to be perfectly capable so far. Usual browsing/YT/iPlayer as well as work stuff which includes spreadsheet apps – one 3MB file has of the order of 8000 rows, each with about 10 formulae so around 80,000 calculations which are done in the blink of an eye.
It’s got an integrated Intel HD graphics chip so it’s pretty basic from that point of view but i3 processor, 4GB RAM, 750GB HDD all seems good value for £400.
Downsides? Plasticky (though v. light), keyboard has begun so squeek a bit, battery life not great. May or may not be deal-breakers.
Pleased so far.