I am looking to buy an MP3 player, with at least 20gb. But, which one do I buy?
An Ipod is an obvious choice, but there is also Creative and Sony players.
Which one do you think is the best?

None of the above...I just purchased the Iriver H10 20gb...and it is flipping awesome. I bought it off of ebay from America and it came very quickly VAT free. I got it from the states because the 20gb version is not available here in the UK. I have had NO problems with it. I have owned MP3 players before from Iriver and they're great. Check them out on the web (a good sight for reviews is mysticriver.com). GL.

I would get an iAudio M3/M5 or X5 depending on your requirements. I have an iAudio M3 and you can pick them up for around £179 now. Great slim player with loads of features, direcect encoding FM radio etc.. I just love it..

I am after a case for a ROKR has anyone got one of these?

http://www.pleasecanihaveone.com/acatalog/Motorola_E1_ROKR_iTune_Phone.html