I was given a Mr Potato Head for my birthday, and whilst I was in Disney last month, I picked up the Buzz, Woody, Starship Trooper and Darth Vader accessories for it.
Kids, no idea, probably some plastic shit to do with Harry Potter?
For adults a Kindle which I hadn't even heard of a week ago and I'll be mighty pissed off I don't get one. Actually I won't I'll go and buy myself a non 3G one on boxing day
Lego, a netbook (age depenant - perosonal choice as to when they are ready to have their own computer) any one (or more if your offering!) of the big 3 games consoles.
That'd all suit younger kids
But for me
Its some shoes from my mum and her boyfriend, and 50 quid each from my mum and my dad, and probably an away day paid for by my dad.
The 100 quid from my parents goes with 100 pounds i'm saving from work/EMA and will pay for an Acer Liquid A1! best cheap android phone going, i'm sure it can be hacked to run 2.2/3 when it comes out and if not i'm not that fussed. And maybe a second hand iPod touch too since I enjoy jailbreaking it.
Oh and a free house, booze, Iceland platters and loud music. Thats a great gift.