Take Spiderman-Man, combine him with the famous Helicopter game, and you've got Grapnel. This is a game that somehow borders on perfection; completely engrossing, completely addictive, exhilirating, and amazingly simple.
This is a game I will end up spending hours playing, usually without even thinking about it.
It's only flaw is in the unlockables; there are some really awesome ones that make the game even better (Accelarate and Rubber Floor, I'm looking at you) but many aren't very good. Geting the money to buy an unlockable is hard enough, worse that the one you decide to buy might end up being a waste of time.
Clean Asia! is seriously awesome. The story involves giant alien eyeballs attacking Asia, and so of course the only method to defeat them is to send a lone pilot out against them in a super-cool spaceship. Whatever.
The game has two different ships from which you can select, the Reflector and Attractor. Of the two, the Reflector is the more classic ship and was the one I used first. But the Attractor is where things get cool. Its only main attack is a short ramming attack. It can blast through parts of the enemy ship, shattering them into a hundred tiny squares... and then with the second button, it draws the enemy's shattered pieces toward it, like a giant vortex of multicolored squares. Once you've got some enemy pieces floating around you, you can fire them one by one with the ram button, or--my personal favorite--just let go of the attractor, unleashing a storm of squares that does massive damage. And then, naturally, the enemy will shatter apart more and you'll have more pieces to fling at him.
Combine excellent SHMUP gameplay with excellent vector-y graphics, three totally different totally crazy fun levels, and some kickass music to top it off, and you've got one hell of a game.
The Hanrahan Game is straight-up well made action with a storyline that is pointless yet engaging. The graphics and music aren't spectacular but they work; the game does a good job at keeping things varied with many different locations and colorful environments. At the core this game is fun because of the awesome swordplay and enemy physics. When killed enemies go flying around in a hilrious mess, and you feel pretty badass running through a group of enemies, throwing them about like a demon. There's also a nice subweapon feature that opens the doors to some really cool extra attacks (particularly those of the explosive variety). The only major flaw in this game are some poorly designed bosses.
Shotgun Ninja sets itself apart from the other games on this list as being the only I've actually managed to finish. This is partly a testament to how short it is, but even more a testament to how much fun it is. Slippery platforming with some awesome features like sticking to the ceiling, combined with fun shotgun/grenade kills makes for really fun gameplay. The graphics and sound are awesomely retro, and the music is particularly catchy and fun. Not to mention a hilarious plotline and engaging level design.
The only moment in which the game loses its magic is during a couple of the particularly long levels; getting hit once kills you, and dying makes you respawn at the beginning of the level. This leads to some huge frustration, but the game's sheer awesomeness made it bearable for me to play through the same level 15-20 times.
Those are my favorite Game Maker-made games. As I play more games of interest I'll probably be posting about them here.