They're both excellent and I use them both. I would go for Yahoo though, simple because it's easier to group your mail into folders. Still can't get it to send and receive from my own domains emails though.
Thanks everyone for participating in this little poll. I didn't include hotmail because I hate the way it's tied to MSN Messenger. I guess I should have anyway.
Gmail all the way common theres no competion there Its fast, simple, easy to use, more webspace, has alot of features which other providers dont offer.