Asda have a selection of singstars at bargain prices:
PS2 - Queen, Abba, Boybands vs girlbands, summer party, singalong with disney, 90s, R&B, Pop hit, ballads, rocks and Bollywood all @ £11.91
80s and party @12.91
PS3 - Next Gen, Queen and Abba @17.91
Free delivery on all.
Note that Queen is a pre-order at the moment.
Good prices all round really, especially the PS2 ones and the fact you can now use them on the PS3 is great :)