Here's a list of 100 indie games that I've enjoyed. This list includes freeware games, shareware games, Japanese indie import games, mods, and works in progress (WIP). It does not include browser games. I've tried to spread different genres more evenly around in the list so take the order as more of a general idea of how they rank than an absolute win/lose situation. This is not an exhaustive list and I encourage anyone with games that I forgot to post them in the forum.
#74 - #50!
#74 Plasma Pong (Freeware)
Beautiful game in which paddles battle by squirting fluid at the ball. The main site was shut down by Atari for infringing on their copyright and losing the company millions in pong-related sales. Luckily it's still available at the link above. My German is a little rusty, but I'm pretty sure "Zum Download" is the button to press.
#73 Star Wars: Battle of Yavin (Freeware)
Fly as Luke Skywalker along with 30 X-Wings and Y-Wings assaulting the Death Star. Simplified flight controls can be controlled with WASD and the mouse. The game is at its best when it breaks canon and adds battles against the Death Star's Star Destroyer escort. The graphics update linked to on the same page is highly recommended (Damn near necessary for the trench run), but you need to install the game to the default Program Files location for it to work.
#72 Crimsonland (Shareware)
Robotron-esqe survival game. Killing enemies gives you experience points you can spend on perks that give you new powers. There is also an earlier Freeware Version still available.
#71 Hakaiman (Freeware)
Metal Gear-alike with neck snapping and a copious amount of grenades in place of all the yak yak. If the game won't run, change the name of the executable to something in English.
#70 Zelda Classic (Freeware)
A clone of the original NES Legend of Zelda with a full host of dungeon editing tools that has lead to a huge database of quests, many with improved graphics and new items.
#69 Chalk (Freeware)
An experimental shmup where the player fights against enemies and obstacles by drawing chalk lines over the screen in various ways. I suggest using WASD for movement to free the mouse for drawing.
#68 UFO: Alien Invasion (WIP)
Open source clone of X:Com. A new version just came out.
#67 G-Type (Freeware)
Fan-made combination of Gradius and R-Type. Note that the difficulty level affects the powerup dynamics.
#66 The Chzo Mythos (Freeware)
A series of short horror adventure games by the author of Zero Punctuation. 5 Days a Stranger, 7 Days a Skeptic, Trilby's Notes, and 6 Days a Sacrifice. It starts out merely decent in the first 2 games, but really takes off in part 3. The ending is brilliant.
#65 Fren-Ze (Shareware)
Dirt Cheap abstract shooter with really pretty vector graphics. The odd thing about it is while it does pour gobs of bullets onscreen, I would define it as more of a memory shmup than a manic shmup, especially with how regularly the bullet swarms move.
#64 Necrotic Drift (Freeware)
Totally sweet text adventure game that mixes Caltropsian comic stylings with a setting that rewards the player for having a nerdy childhood surrounded by exotic dice.
#63 Hurrican (Freeware)
Snazzy update of the Turrican run and gun platformers from a variety of systems.
#62 Torus Trooper Pure (Freeware)
The original Torus Trooper by Kenta Cho was a tube racer/shooter with an incredible sense of speed that was unfortunately way too easy. Luckily, Kenta Cho releases the source to all his games and a fan created this fork. Speed is now tied to the number of enemies you destroy, the game is WAY more challenging, and it's even faster!
#61 Titans of Steel (Freeware)
A PC version of the board game Battletech that happily breaks canon in the name of fun, adding things like napalm missiles, cold light lasers, and anti-energy-weapon shields to create a more balanced and interesting game. The initiative system tracks moving and shooting independently, but after you get used to it the system avoids a million initiative-based headaches from other games. It also includes the option to play the game as a strategy RPG, but bear in mind your pilots start out laughably inept.
#60 Starships Unlimited (Shareware)
Space 4X that mixes a little Master of Orion, a little Heroes of Might and Magic, and a little Starfleet Command while de-emphasizing the boring parts of 4X games. Make sure you set the options so that by default you handle combat.
#59 Oasis (Shareware)
An interesting mix of Minesweeper and early-ages Civilization. Use clues to uncover valuable hidden resources, then use these resources to build your technology and population in preperation for defending against an attack by barbarian hordes.
#58 Flatspace II (Shareware)
A 2D asteroids-esque "Elite" alike that randomly creates a galaxy every new game. The really interesting thing is that ship traffic is not randomly generated when you enter a secor. Every single ship in the galaxy is independently tracked and carrying out its own individual jobs at all times.
#57 DOOM RL (Freeware)
Ha! Someone made a Roguelike out of Doom! That's right up there with Progress Quest as one of the great joke games...
...except it's actually really good. All the tactical nuance of nethack combat, along with artifacts and hidden areas and character perks, none of the annoying hunger levels and other headaches. And development is still ongoing.
#56 Slay (Shareware)
Deceptively simple hex-based strategy game. The trick is that disconnected territories don't share their economies and untis without sufficient supply automatically die. So if you rampage too far out with your superpowered unit and get cut off from your main supply store, your expensive unit is lost.
#55 Neon Wars (Shareware)
While you're trapped in an arena continually filling with deadly abstract vector shapes, each of which has a distinct pattern of movement, this is not really a clone of geometry wars. Shooting and aiming are handled automatically, the player's job is to control the ship's movement (which maps directly to mouse movements). You dodge enemies and collect tiny powerup stars that are destroyed if you let an enemy touch them. It's a game of dodging that almost has more in common with bullet hell shmups than robotron. But do yourself a favor and turn off the ugly background tiles.
#54 Critical Mass (Shareware)
Turn-based tactical combat game where you control the wing commander of a squad of starfighters and engage in pitched missile dogfights over a huge variety of randomly generated missions.
#53 Lugaru (Shareware)
Kung fu rabbits with ragdolls. The stealth kill with a knife is called "tracheotomy." While the main campaign is really short, there's a fantastic and bugtastic fan-made expansion that's almost twice as long and comes highly recommended.
#52 Battleship Chess (Shareware)
Like the title says, a WWI-era mix of Chess and the boardgame "Battleship." At the title screen hit F3 and type (in caps) "ADMIRAL" unless you want to spend 20 hours trying to unlock the game to full functionality.
#51 Phantasmagoria of Flower View (Import)
2-player splitscreen Bullet hell shmup by Shanghai Alice. Actions you perform on your side create bullet patterns on your opponent's side. Victory is a matter of endurance.
#50 Global Defense Network (Shareware)
A shooting gallery game where the recharge rate of your weapon and the appearance of targets are tied to the beat, forcing you to get in the rhythm of the song to get a High Score. It's one of the best non-"Simon" music games since Rez... sometimes. Unfortunately it only gets things right with about 2/3rds of the songs.