Well I use web mail (squirrelmail) for only business purpose. For personal use I prefer Yahoo mail, because I don't like to use Gmail. FYI, just 2 days ago I was trying to send some pics to my friends and once again Gmail showed its freaky nature.
I switched a few short years ago from Outlook to Gmail, which I decided on after looking through most of the popular web-based clients (free and paid). I thought to myself why the headache of running your own mail server, following up on updates, etc when Gmail has a very active development team behind them.
I haven't looked back since. Gmail is focused on productivity and I noticed just how much more efficient my days have become after I settled in and set it up as per my requirements.
If you run a service, product related website then it is advisable to have Email account with your domain name like markruber at yourwebsitename.com.. Even medium and large organization use their company name for Email. Gmail, yahoo, Hotmail are just for personal purposes.