I've gotten off of XP on my 5 computers at home. I have one running Vista and the other 4 are running Windows 7. I do have XP installed in separate partitions I can boot it on 2 computers, and XP mode (under Windows 7 Pro) on another. The only Windows 8 I have is on my test computer which has XP, 3 versions of Windows 7, and Windows 8 Pro. I would really recommend Windows 7 Professional for anybody needing XP, since it has a free XP mode which works well for all XP dependent programs except high speed games (graphics are too limited for these). At the very least everyone should be aware of what they'll need to do to get upgraded. If you're going to get Windows 7, now's the time to get it because almost all new computers are being shipped with Windows 8 preinstalled.
With Windows 8, there're no games, no XP mode, and a considerable learning curve. Thank goodness there's Start8 and Classic Start from 3rd parties which make Windows 8 have the look and feel pretty much like Windows 7. If you're going to upgrade to Windows 8, you should download it this month while you can still get it from MS for $40. After this month, it'll cost $70.
Light bulbs you shouldn't buy
There are plenty of dimmable LED light bulbs, but make sure you don't buy the ones that flicker when you dial them down.