Here is a couple of cool flash games to have a go at (plus some scores to beat!)

Flight Sim X
Flight Sim X
Play paper aeroplanes around the office without the paper! Try to get the plane out the window for a huge score. My best is 101m.

Finger Fenzy
Finger Frenzy

Think you can type fast? Easy as ABC? Can you find the missing R in frenzy? Well, in this game you must type the alphabet, A to Z, as quickly as you can. I got 4.172, can you crack 4 seconds?

www.nationstates.net

NationStates is an online game that lets you run your own nation. You deal with the different issues your nation faces and your choices result in the civil rights, economy and political freedoms increasing or decreasing accordingly as your population grows. You name your nation, as well as it’s currency and national animal (which can also become the nation’s favorite snack), you even get to create your own flag.

NationStates

You’ll deal with problems ranging from crime and health to education and the environment, with new issues arriving everyday for you to govern over. There are also the NationStates forums where you can chat with other Nations about issues and get involved in International Incidents (you can even declare war) which role playing fans should enjoy. Then there is also the NationStates General forum where you can find plenty of political, religious and all sorts of other ‘discussions’. Lots of fun!

http://fretsonfire.sourceforge.net/

Frets on Fire screenshot

This one is for all the Guitar Hero fans out there (which is a lot, considering the franchise has made over $1 billion in North America alone). Frets on Fire is a free, open-source game for the PC inspired by Guitar Hero, the gameplay involves emulating playing a guitar by hitting the right notes as you strum along, getting the right rhythm and timing is key. To play Frets on Fire, you can use your keyboard instead of a Guitar Hero controller by flipping it around and using the F1-F4 keys to hit the notes. However, you can use the official Guitar Hero controllers too! Some will plug straight in via USB while others (like the Wii version) might require a bit of tweaking but will work wirelessly and give you the feeling of playing the regular Guitar Hero with all the benefits of Frets on Fire!

Frets on Fire

What are the benefits exactly? Well apart from being totally free, there is a dedicated community supporting Frets on Fire, creating mods, skins and (best of all) tons of custom songs to play! Not only can you find the entire Guitar Hero back catalog of songs but plenty of other tracks by different artists. You can even make your own songs to play with the built-in song editor. A great place to start finding custom songs is the Frets on Fire wiki and the Frets on Fire fan forum where you can find hundreds of songs, including different difficult levels to suit new players all the way up to rock legends.