A very ordinary question was promoted to the WebmasterWorld home page, making for a great discussion on TLD, top level domains. The question is, does Google prefer a .com over a .biz, or a .org over a .edu, or .de over a .co.il and so on?
The thread first points to examples of all TLDs ranking well. For example, a search on the keyword germany has the top ten listings in Google as ,org, .de, .de, .info, .gov, .com, .org, .com, .com, and .com. Plus there are many more examples, both "long tail" and very generic examples.
The issue comes where some TLDs are abused by spammers cause they are much cheaper to buy or when you are buying a name on a lesser known TLD when someone own's the main TLD. I personally tend to trust .info domains a lot less because I have seen comment spam after comment spam and most are from .info. Also, most people tend to type .com when looking for something, so having a non-.com version can hurt you there.
We have been through this discussion in the past. I do however recommend checking out the WebmasterWorld thread.
Forum discussion at WebmasterWorld.