Our gift went out three weeks ago and is already set up and running under the Christmas tree in Seattle. The set, a Lionel LionChief Harry Potter Hogwarts Express, found at a local auction had been opened but never run, the cardstock protectors still between the trucks and bottom of the car bodies, no sign of wear on the wheels (I don't think they ever touched a track). My fiancee's 30 yr old daughter, a huge Harry Potter fan, was suprised and is thrilled as is her fiance (her dog and cat maybe not so much but appear curious from the Facetine calls). Funny I tried to find this set "used" for three years at a reasonable price as the fiancee' thought $389 for a new one a bit expensive but I lucked out this year. The set in it's original box with all components cost me just under $50.00, the shipping was another story, $110+ from Virginia to the Pacific Northwest.
As for other Christmas trains my nephews (the oldest now 17), my younger brother's three boys, have each gotten a separate sale Lionel engine (NY/NJ Metro Area road names), matching K-Line smoking cabooses to start, and each year after additional rolling stock, a motorized unit, and buildings from me for Christmas. The initial rolling stock and accessories for the boys was purchased by my mother and younger sister as Christmas gifts. All three boys now have their own unique set comprised of Lionel, K-Line, and Industrial Rail boxcars, tank cars, reefers, flat cars etc. One boy, the oldest, got the NYC streamline passenger set released in the mid-2000s for Christmas the first year to compliment the NYC steam engine I bought him.
My sister, nine years younger than me, has her own set, an uncataloged Macy's one with steam engine (headlight/smoke unit/whistle tender) from 1960, I found listed in NYC's Free Press newspaper for $50 and snatched up quickly while "in the city" one day, that was one of her Christmas gifts from my mom and dad (both now deceased) in the early 2000s.
As for my fiancee' and I we added an Industrial Rail reefer and a lighted non-operating Lionel poultry dispatch car this year to our fleet for under the Christmas tree it'll be pulled by my recently serviced Lionel #2056 steam engine with reproduction Williams tender. Now to add a K-Line bubbling water tower and K-Line rotating searchlight if I can find both at a reasonable price.