I’d say you’re more likely to get the email address you want (rather than myname98327492@gmail.com)if you use outlook.com
It also looks more professional to those who may consider gmail to be a bit unprofessional (I know this is not the case, but there are still people out there that think if you have a free email address then you’re not to be taken seriously) whereas the clear microsoft link with an outlook.com email address can lend some weight with people who are not that techno savvy.
TO be honest there’s not a lot between the various suppliers these days if you’re using them through an email client (and not their web interface) so you can really just go with what you prefer. There are pro’s and con’s for them all.
These points may not be worth considering if you’re just going for a personal email address