I have had a samsung d900 on vodafone for 4 months now, and cannot fault it. Loads of features. Check out the link below. It looks fantastic, and i have had loads of people asking about it as they like what they see!
Vodafone live's service on this phone is really suprisingly good for a wap service. Easy menu, but you can customise your phone to a great extent if that is what you like to do. The only down-side is that it doesn't have an fm radio, and internal memory is only 256mb (although i have upgraded mine to 1gb using a micro sd card)
http://www.samsung.com/uk/products/mobilephone s/mobilephones/sgh_d900zkao2u.asp