Oh God, I love it.
WARNING UBAR SPOILERS FOLLOW
Another excellent entry in the Half-Life saga. The G-Man returns and for once the bastid offers more than vague shit about his employers. Plus, there were some quite fun action sequences, such as the repelling of the attacking Antlions in the mines and the battle of the Striders near the end. When they killed off Dr. Vance, it was truly a sad moment. My one disappointment is that they didn't include a teaser for Episode Three, like they included Ep. Two's teaser with the end of Ep. 1. I'm srsly looking forward to Ep. 3, though; I can't wait to trash the Borealis and tell Dr. Mossman that her boyfriend died.
Truly great. You run around in Aperture Sciences test facility or something and make portals. Aperture Sciences are actually an entity which competes against Black Mesa scientifically, and they owned the Borealis (look up, fool), so they're going to play a significant role in Ep. 3 most likely. (Hopefully, Gordon will get his own portal gun). And the song that plays during the end credits is too awesome.