I'm going to go against the tide... I had many problems with Gmail :
- Gmail filters some file formats, I even had a simple mp4 video filtered, the recipient never got it ;
- Gmail reads your email content and extracts keywords in order to target ads at you ;
- Gmail asks you new personal data (like your cell phone number for exemple) regularly and if you don't give it, you won't access your mailbox any longer, not even with Outlook / Thunderbird or another email client software ;
- Gmail is capricious with email client softwares (I had big problems with that personally) and you often have to access it through webmail ; it's even worse with hotmail for that part ;
- Gmail filters some emails as spam and it won't even go to the spambox, it's directly deleted, no matter if the sender is actually not a spammer.
With Hotmail, in addition to having to access it through webmail quite often, it's also a very slow server, and use its settings as a POP3 account is quite hard to do, if not impossible recently. And like Gmail, it sometimes treats normal email like spam, but contrary to Gmail, these emails always go to the spambox instead of being directly deleted, so you can still retrieve them in time.
I used Yahoo until a few years ago and i didn't have any major problem with it.
And yes, it's best that you have an email account for "normal emails" and a second account especially for online stores and potential spammers. If you're using your main email account for online shopping, it's going to be full of spam sooner or later.