There are quite a few domain extensions out there now some of which look professional and then others that don't look so professional in which many avoid using.
Which domain extensions do you tend to avoid when purchasing a domain? For me it would be .info, I really don't feel that extension looks professional or even very inviting so it's one I avoid if I can.
Controversial, I know, but I would say to stick with .com, .net and maybe .org. Country code domains are good if you know the market and usage of that specific country and can validate whether it would be a wise investment.
Another thing to consider is domain name hacking, where you use a country code or other extension in order to end a phrase:
https://en.wikipedia.org/wiki/Domain_hack
Then you're really in uncharted/able territory and you're talking about brand awareness
!
I find .info to be very unprofessional looking if I am honest and is one I always avoid if possible. I see people using this extension because it's the only one available for the domain they want. If that is the case then .com and .co.uk and even .net and .org which are better extensions are all taken by someone else and it will affect your chances of getting decent traffic.
It is debatable part. You can not answer it properly, because your business activities are important.