If you like Draw Something then you should get this, as it's superior in every way except that it's not available for android I believe.
Benefits over Draw Something:
1) With the full version (currently free) you get all the colours straight up and don't need to pay or earn 'coins' to unlock them
2) Many different brush styles (eg. spraycan, fill)
3) Many different words
4) Can play games with more than 2 players!
5) Can play live games online against 10+ players all guessing as someone is drawing
6) Different gametypes
Same as isketch.. but you need a good internet connection and fast typing skills..
Different games.. wouldn't compare them to say which is better..
drawsomething is turn based..(taking turns and take ur time)
charadium is real time..(happens on the spot and time is constrained)