Overview
Tower Defence Games are a genre that has been around for a while and is steadily growing in size and breadth. Which ones should you get for what platform?

Tower Defence (TD) Games are are games where multiple types of enemies, with different strengths and weaknesses, emerge from one or more points and make their way around the screen to your base. If they reach your base they inflict damage. To try to prevent them from reaching your base you build towers of various types with various abilities to kill them on their way past.

TD for the PC
There are more options for TD on the PC than you would believe possible - from simple flash games like this one:
http://www.handdrawngames.com/DesktopTD/Game.asp

To full on Multi Player experiences like the ones on this site:
http://www.towerdefence.net/

The best TD experience going around on the PC has to be the custom maps based on Warcraft 3 and it's expansion The Frozen Throne - you will need both to get the full experience but once you have both you will have literally hundreds of great tower defence maps available to you - one of the best sites for downloading them is here:
http://warcraft-maps.com/

But there are so many sites to get them from it's not funny!

We had a LAN recently where four of us spent about 12 hours playing Warcraft 3 TD maps and we hadn't even played 1/10 of the maps we had already downloaded - that's why the site above is handy - the maps are rated and the ratings can generally be relied on.

While you're playing stuff on Warcraft 3 and the Frozen Throne you should also check out DOTA - I'm not about to go into it here as it's is its own series of articles but you can get it here:
http://www.getdota.com/

TD for the PS3
PixelJunk Monsters (which I reviewed here: http://www.xomba.com/pixeljunk_monsters_review_ps3_psn) is one of the best examples. Other options include:
- Comet Crash (adds an offensive twist to TD)
- Savage Moon

TD for the Wii
I haven't played any titles and don't know much about TD on the Wii but I believe there is an upcoming WiiWare title called Robocalypse Beaver Defense.

TD for the XBox 360
I can't really comment about the XBOX360 too much as I don't own one and neither to any of my friends that I game with but a quick google reveals that Defense Grid: The Awakening is apparently a fantastic TD game that's also on the PC via steam.

TD is FUN! Play the flash games (lots more of them here:
http://gaming.hexus.net/content/item.php?item=14591&page=1) and get into it!

Mr Staypuft
Old School Gamer

My Xomba Articles:
http://www.xomba.com/user/slewis68au