I am sure this has been covered before, but I would be interested in other's opinions on whether .com rank higher than .org and etc, and going further into country codes.
I am an Aussie, so for my country I am 100% convinced that .org.au are weighed down in the SERPs. I have a .org.au site myself, PR5 with keyword domain name - yet I only appear on average around positions 50-60. I just found another .org.au site relevant to what I was searching for, again with keyword domain and PR7 - probably the best site about the content I was searching for - yet was positioned 35 in the SERPs. Above that were PR2 and PR3 sites with minimal information.
Doesn't stack up for me, as Australia has very stringent regulations on registering domains, and .org.au are (usually) authoritative sites run by organisations.
The Purpose of ccTLDS are as Country Identifiers..by using .DE , .com.au , .co.uk etc...you are telling the search engines that you are interested in geo location traffic (whether thats what you really mean or not) .. that's why you'll generally rank higher in Google.com.au rather than the GENERAL index .
You use ccTLDS specificaly to target geo location traffic , if you want to rank higher in Google.com.au then the first step is use the ccTLD for that location.
If you want to rank better in the general .com index of search engines then use a global TLD .com,.Net , .Org
Some ccTLDS are treated as GTlds .Tv , .Ws , .Cc ..because they are marketed as such
These are just general guidlines, with enough links from the global addresses your ccTLD can rank just as well in the general Index as well as the geo index.