This same question has been asked several times recently. Try a search for more details. The consensus seems to be go with the Nexus 7 based on bang for the buck unless you need the features it doesn't have (rear facing camera or sd card for example).
There are two other 7" Samsung tablets (7.0) a d I have heard rumors that Samsung is going to be releasing a 7" Note series tablet. I might wait to see if there is any truth to this rumor, but most of Sammy's 7" tablets are over 6 months old, so they should be dropping a new one any time.
thanks for the info i think ill look at the samsung just because of the rear cam the best price i can find is from laptop direct [h=1]Samsung Galaxy 7.7 32GB Android 3.2 Wi-Fi Tablet in Black - GT-P6810[/h]
at £249.00 inc vat is this site safe as it seems a little low ?