#1 MineSweeper Java implementation with three levels of play, and an online hall of fame, which requires two games with a low time to emphasize skill over luck.
The Authoritative Minesweeper World records at all 3 levels, a few tips and cheats, and many links to software and related pages.
Hex Minesweeper Variation on a hexagonal grid. Windows 95 shareware.
Hexatron Variation of Minesweeper with hexagonal grid. Java applet.
The Minesweeper Handbook This handbook teaches how to play better Minesweeper, taking you from the fundamentals through to advanced concepts.
Planet Minesweeper Contains advice, cheats, rankings, downloads, and a forum. [English and French.]
MineSweeper3D Windows implementation of minesweeper on the surface of a 3D polyhedron, with challenging new tilings, and many boards to choose from. World records maintained online using encrypted submission. Built-in auto-solver. Demo version available.
Bomb Hunter Commercial mobile-phone version of Minesweeper with new tools including probes and a radar.
Crazy Minesweeper Windows shareware implementation of Minesweeper and a new variation in which new types of mines contribute 2 or 3 to the number seen in adjacent squares.