smugmug is my favorite.
and excellent customer service, they generally reply to an email within minutes.
i tried the 7-day trial and didnt look back. my flickr account went by the wayside. i never liked photobucket or imageshack. i simply found smugmugs interface, customization and overall look to be the smoothest.
if you join up, use me as a referral, you get 5 bucks off and i get 10.
simplyathos at gmail.com
you can see my smugmug photo page in the link in my sig.