In that sense Yahoo is much better - a couple of years ago I registered an account to allow me to test my client's email setups - it hasn't had a single item of spam in all that time.
I have another regular account with Yahoo which I do use - and is the one I give out to people I don't trust - that one gets 1-400 spams every couple of days, but 99.5% get filtered out automatically and then get deleted automatically by Yahoo every time they reach a certain size in kb (one of the options on the system).
The sign-up process is a lot easier too.
Charles