Email addresses for research assistants What is the best email address for a Research Assistant (RA)?

I noticed that most of the RAs and faculty in grad schools use their first name only as an email handle, like: firstname@school.edu.

However, as far as I know, the "perfect" professional email address would be like: FirstnameLastname@school.edu.

Only few of them used this format but with a dot in the middle, like: Firstname.Lastname@school.edu.

I think it might be neater to use the firstname-only form, but is it still professional to use it?

I'm sorry for this silly question, but I would appreciate your clarification.
Most schools don't actually give you a choice: they simply set you up with a standard email address following their standard format.  Often this is some combination of first name or first initial plus last name, though I've even seen some schools give everybody a horrible alphanumerical mess as their official email address.  Many places will then also give you an option of setting up one or more email aliases, which you can use to modify the default.

Personally, I think that anything that includes your last name (and nothing else bizarre) is pretty reasonable and professional.  For my own case, for example, one can reach me in various locations with various forms of "beal", "jbeal", "jakebeal", "jacobbeal", and "jacob.beal", all of which convey the same basic information of "yes, this is who you think it is."

It is worth noting that, in some circles, being the one to get your first name or your initials on a system can be considered particularly special.  This is because it can indicate that you had been a very early adopter and/or involved in the system's development.  That's unlikely to be the case for most RAs at a university, however.