Buying someone an actual bike component as a Christmas gift will, of course, result in them disappearing off to the garage for much of Christmas Day to fit it. Or, if things go smoothly, just a bit of Christmas Day with the rest of it spent out "testing". That may or may not be a good thing, but if you're looking for a bit of bike then something that'll make a real difference to the ride is the way forward. Like, for instance, new suspension forks.
Like dogs, forks shouldn't just be for Christmas. So you'll be wanting to choose something that's known to be reliable. Which in the world of forks means Marzocchi is a safe bet. The MX Comp is available with 85 or 105mm of travel and features air preload and adjustable rebound damping. With a crown and sliders borrowed from the lightweight Marathon it's not too portly for a budget fork either.