Spider solitaire on the computer.

I was in the same situation, and for a time, I had a slight addiction to Pyramid solitaire here is one of my favorite versions. It's a little different than traditional solitaire - all of the cards (including face cards) have a value. Half the deck is arranged in pyramid format, half is left in a pile. You need to match up your available cards into pairs who's value total 13.... Queen and Ace, Jack 2, 10 3, etc. Kings can be removed on their own. You can pair up 2 cards from the pyramid, one from the deck and one from the pyramid, or you can pair up 2 cards from the deck. There are always 2 cards available from the deck, and you can use the older card to move backwards through the deck. If neither card can be used, you flip forward through the deck. It's ADDICTIVE so be careful!

Some of my other favorites come from neopets.com.... no joke,, I'm 20, and I still play neopets. The site is full of simple flash games of all types - typing games, math games, strategy, etc - some of their games are traditional games that you'd find on other sites, and some are unique. If you can bring yourself to sign up for a site designed for 13 year olds they have tons of great games available (my favorites are meerca chase - very fun and mindless).. and on the plus side.. there is never any nsfw ads because the site is make for children.

Third - Zuma! I used to love this game. Basically there is a rotating gun... thing... in the center with several colors of balls. There is a track coming towards the center with more balls rolling inwards. You use the rotating gun... thing to shoot the oncoming balls - when you match colors, the balls disappear. The earlier levels are easy, the upper ones are a little trickier.. and you definitely need a mouse! You can find it here

Last - desktop tower defense. It's a pretty typical tower defense game (if you've ever played tower defense) but there is something about this one that makes me love it more than the others.. maybe because it's actually possible to win fairly easily on the early levels. I personally like the earlier versions better than the newer ones - but that's just me. You can find it here

And of course, a classic game of tetris is always good!

Enjoy!

It's longer than a couple of minutes at a time, but I like to play chess.

The server I use is below, and is one of the best and most popular, though you do need to download a free client to play.

http://www.playchess.com/

There are other sites that allow you to play online without downloading anything.

One good thing about chess is that pretty much all sites support the use of chess clocks, in which you can set a time limit for the entire game. I usually play a time limit where both sides have a total of 3 minutes for the entire game. That way the game cannot last more than six minutes whatever happens, and usually it's over in 4-5 minutes. Chess sites also usually support a rating system, to help find players of the right level.

The only disadvantage is that on sites like playchess.com if you are not a decent player, you're liable to get your butt kicked. :)

The other "disadvantage", but I guess it's inherent to all good games, is it can be kinda addictive, so perhaps best not indulged in when you have pressing work to get on with.

Here you go,

http://www.freerice.com/

You can play one question at a time, it donates to charity, and if anyone ever catches you playing it you can explain that it improves your vocabulary, an asset at any job.

I told my boss about it and she loves it.

http://www.freepoverty.com/

This one has a similar idea, but it does take a tad longer to play as you are answering timed questions.

Have fun!

you can try digital chocolate's "Rollercoaster Rush 3D" or "Tower Bloxx 3D''. I hope you will enjoy both games.

Link:

      3d Tower Bloxx > http://www.digitalchocolate.com/games/mobile/3d-tower-bloxx.html

                            iphone > http://www.digitalchocolate.com/iphone/#tower3d

      Rollercoaster Rush 3D > http://www.digitalchocolate.com/games/mobile/3d-rollercoaster-rush.html

I like "Trap the Cat", it is a quick little, addictive game. You can find it at: http://www.internetgames247.com/playnow-6975-Trap%20The%20Cat%20Game-Flash_Game.html

This is perfect for a quick diversion. Kind of like passing the time doodling. Short, sweet, and addictive! Enjoy...

try Facebook applications.

like mafia wars,farmville, yo ville etc.
there are lots of games to check out and u can also enjoy the advantage of social networking

well there is not much to worry abt the game being watched.
u can just close it and then login again after ur boss goes away.
:P

.these games require u to do certain activities over a period of time.
make it regular and enjoy ur sweet work hours

When I need a game to play oin a break I like the facebook games jungle jewels and bejeweled blitz. They are match 3 games and can be quickly played.

http://goodexperience.com/games/ has a nice, edited list of games which offer a 'good experience' according to the maintainer.

Plenty of gems in there which I enjoy.