We bought this one today from John Lewis - have been having a play...love it so far!!
http://www.johnlewis.com/bt-digital-video-baby-monitor-1000/p231458726
The sound is great and very clear - and the screen is quite big, with a really great camera view. Also has night vision, room temp gage, lullabies to play to baby and a two way talk back so you can speak to LO without getting up to soothe him/her too.
Hope that helps xx