Every possible .com name 1, 2 or 3 character long is taken. Every English word is taken. Some 4-character names are still available that include numbers (I recently registered p3ml.com).
But there are many excellent names with common suffixes and prefixes that are available!
Consider the following patterns.
Common Prefixes
e
elance.com
o
odesk.com
Common Suffixes
r
farmviller.com
base
visionbase.ca
labs
peanutlabs.com
ly
massively.com
.com Alternatives
.net
battle.net
.ly
bit.ly
friend.ly