What registrar do you use and why?

[domaingeezer]

There are so many different registrars to choose from.

What different benefits do they have?

i.e. are some better for .coms and others better for .info's?

are some better for bulk buying?

are some more expensive when it comes to renew domains?

are there any I should avoid at all costs and why?

Which ones are the most professional?

If you can answer any of the above I would much appreciate it

Thanks in advance