If you didn't remember and didn't happen to drive past lines and lines of people waiting for the midnight release, Diablo III was released today. Blizzard stuck to their release date that they gave back in March, and for a cool $60 the game can be yours. If you don't feel like getting a physical copy, you can buy it directly from Blizzard as a digital download. Links to that are in the announcement.
If you're a big fan of the Diablo series, you may want to look into the Collector's Edition. For $100, you get quite a bit. For one, you get the game, obviously. You also get a 4GB "Soulstone" USB flash drive with full copies of Diablo II and Diablo II: Lord of Destruction. You also get in-game items for Diablo III, World of Warcraft, and Starcraft II. For Diablo III, you'll get glowing angel wings, an exclusive banner sigil, and Bottled Cloud or Bottled Smoke dye for your armor sets. For World of Warcraft, you'll get a fetish shaman pet to follow you around. For Starcraft II, you'll get three Diablo-themed Battle.net portraits as well as a special army logo. Other things you get with the collector's edition are a behind-the-scenes Blu-ray/DVD set, an art book for Diablo III, and the Diablo III soundtrack.