The best PVRs to go for are twin tuner ones unless you want to make DVD discs in which case you will need a DVD recorder.
A good PVR comparison guide is here.
http://www.pvrjunction.co.uk/compare/
Of the ones listed the Humax 9200t (�180 or so) and Topfield TF5800t (�230) are about the best. In terms of usability I found the Humax very easy to use and so far very reliable, the remote though is not to everyone's liking.
The Topfield is quite advanced and may not be the easiest to use for the newbie. It can do almost anything you want thanks to a programming function called TAPS. This enables you to rewrite the control software to give you extra functionality or download pre written TAPS but is probably not suitable for the novice user.
Have a look on Digital Spy Forums as most of the current PVRS feature on there, you will get a good idea of what users of these machines think.
http://www.digitalspy.co.uk/forums/forumdispla y.php?s=9a18f921dc3c0a9487a7fb4b52f556e3&f=90