I have a used the following:
PDA with orbiter running - looks good, works well but needs to be recharged once a day which means you need a power supply near your coffee table and you must remember to put it back. I think this or a WebDT is what I would use in a Home theatre room
Gyration Ultra Air mouse - good for navigating UI2, I like using the on screen orbiter.
MCE Remote - Good but takes many clicks to get to where you need to go - but is very cheap and probably the lowest risk as far as WAF
TS820 handheld Wireless Trackball - I use these all the time about $50 each, acceptable to most wives, if they are used to a mouse they can use this. they have enough buttons for select (L Button), Cancel (R button), F6, F7, F8, has the bonus of pg up/ pg down on the side for turning media pages. I may be biased because I sell these, but the batteries last like a normal remote. for everyday my wife uses these with all the MD's
http://wiki.linuxmce.org/index.php/TS820Hope it helps