When buying Wedding presents I use
http://www.amara.co.uk
They have a fantastic selection of luxury gifts which are just right for this occasion.
The last gift I purchased from them was a Riedel Sommeliers Decanter which was well received.
http://www.amara.co.uk/Sommeliers+Decanter-611 .htm
Plus I have had the pleasure of its use at a subsequent dinner party!
The gifts they stock are not the cheapest, they only stock quality items, but then who wants to give a cheap wedding gift?