http://www.miniclip.com/games/bloxorz/de/
Cubical puzzler, simple but fun until you reach your frustration limit :P
http://www.miniclip.com/games/bloxorz/de/
Cubical puzzler, simple but fun until you reach your frustration limit :P

http://www.kongregate.com/games/KingDotCom/gluey
Gluey is a small, physics-based puzzler built in flash. It revolves around differently colored blobs that the player has to "pop" to gain points. It's pretty simple but it's smooth graphics and feedback just pull you into the flow. Especially the Zen Mode is great for killing time.

http://www.sophiehoulden.com/games/thelinearrpg/
Linear RPG is a small little pardoy game that makes the structure behind JRPGs visible. It's pretty easy to play, just walk left and right but it looks goregous and is entertaining for the brief time it lasts.
http://www.thegamehomepage.com/play/red-remover/
A well made puzzle game that's worth the 20 or so minutes to sink into it. Well done, funny and intriguing. You'll be sad when you've finished all levels.

http://www.channel4.com/history/microsites/0-9/1066/game/index.html
A historical strategy game detailing the events in England in 1066. You can play a short (3 battles only) campaign against the computer. Here you'll learn something about history and find a feel for the mechanics. Then you can either play skirmish battles or fight against other players.

http://fastgames.com/littlewheel.html
Little Wheel is a small adventure game with a charming art style and goregous animations. Taking control of the sole active robot in a world of metal it's your task to reactivate the generator to bring life back to all machines.

http://www.kongregate.com/games/GlaielGamer/closure
Very interesting game about lights. Carry one and illuminate your surrounding to find new pathways. But be careful or you'll stumble into darkness very quickly! :)

http://www.kongregate.com/games/rudy_sudarto/bug-war
A neat little game about larves and instects, that uses tower assult as a base for a strategic territorial control gameplay mechanism. Easy to learn, fun to play.

http://de.bigpoint.com/mini-games/388/Strawhead-Samurai/
Strawhead samurai is a fighting game where you, as a lone samurai, have to fight an invading army. The main mechanic is slicing by painting lines with the mouse. It's a pretty cool idea and works surprisingly well. The game's a short campaign with a lot of action and some strategy at the end. It's a neat little package that should occupy you for 10 minutes or so. Give it a try.

http://ludomancy.com/games/today.html
Today I die is a little experimental Flash game from Daniel Benmergui. It's about the words of a poem and how changing the words changes the world. Actually it's less of a game and more of a puzzle, since - as far as I can see - there's only one real solution. Regardless it's a nice little timewaster which might just inspire you. And if you like that one, there's more where that one came from on Daniel's website and blog.

http://www.mybrute.com/
My Brute is a small and simple browser fighting game based on flash. Players generate a character and then fight others for experience, items and skills. They can also enter their brutes into tournaments. From my current playthroughs it seems as if players have little options beside initial quasi-random character generation but it's simpleness makes for a good timewaster.

http://armorgames.com/play/1467/virus
An addictive fast-paced vertical-scrolling shooter. It doesn't really look like viruses, more like an old air-force jet user interface gone mad. Still it's a very smooth and fast little shooter, worth a try. :)

http://www.playauditorium.com/
No time for talk since I spent too much time before work playing this game instead of getting myself ready. AUDITORIUM. Found on Penny Arcade and damn is it worth the link.
check it.

http://armorgames.com/play/349/red
An easy to learn skill game where you control a turret and have to ward off falling black orbs by shooting at them so they change their direction. One hit, you die. But there are shields, weapon upgrades and additional turrets that will help you along the way. Also the music is very... psychedelic.

http://armorgames.com/play/1642/epsilon
What a nice puzzle game this is. A lot of inspiration seemingly came from valve's "Portal", but Epsilon certainly has his own unique style when it comes to solving inter-dimensional puzzles with a ball that needs to be sent through a portal to complete a stage. The concept is also easy to grasp, so you can play right away.
http://www.gamezhero.com/online-games/sports-games/orbitrunner-games.html
Orbit Runner. Get working planetary oribts without causing cosmic destruction.

http://www.addictinggames.com/chronotron.html
A time-bending little puzzler. Look how cute you were a few seconds ago! Just make sure your actions don't cause a paradox in the space-time continuum!

http://www.kongregate.com/games/rapaxus/spellblazer
If you like Bejeweled, you will love this game.
It takes the simple mechanics of Bejeweled and wraps them as a battle system into a fantasy flash game.
Swap the different symbols to get three in a row and trigger a spell, that either hurts your opponent or heals yourself. When you trigger symbols your opponent uses for attack, you will get a defense bonus against his next attack.
Graphics and story are also great.
I just hope there will be a second part of this game.