Generally when a television series offers up a Very Special Episode, that episode stinks. Usually the VSE involves some "important" hard-hitting storyline that "proves" how bad drugs are, or some such rot. Occasionally, the VSE involves a break from whatever traditions the series has established, a one-shot step back from the norm. Such was the case in tonight's episode of House.
The structure was more complicated than the average television show, with time-shifting and ... oh, I can't really describe it, how about character-shifting? It might have played as pretentious, but one of the problems with House is that its plots have already fallen into a predictable pattern in only its first season, so this momentary change from those patterns was welcomed, kinda like the musical episode of Buffy.
For most of the season, House has been a decent show, nothing special, with a great lead actor and titular character. Tonight the entire program was up to the level of Hugh Laurie. I don't expect such quality to repeat itself very often, but it's rare for any show to pull it off, and tonight, House was one of the finest shows of the year.