Direct2Drive has some astounding deals on at the moment.
Firstly there's Mirror's Edge which is a staggering £7.50, for a game which is unique and totally underrated by most of the gaming press. One of my favourite games of the year so far, it's almost as important to the future of FPS gaming as Portal was!
Secondly they also have Dead Space for £7.50, which is something I've not played myself but will be soon because of this! I've been reliably informed that this was badly overlooked due to other games released at the same time.
Finally, Mass Effect is £15, also on direct2drive (I should be getting paid for this!) - another one I've not played but will be soon!
They really are good deals I think. I recommend you get Mirror's edge at least, if you don't already have it of course!