Been using Picasa for a while now, but seems like Google is pushing Picasa more and more into their G+ thing, which is fine for when I'm sharing photos in G+, but when I want to just go to an album to find a photo to post on the forum or elsewhere, I want the standard Picasa layout. Haven't checked out flickr since their recent update, don't store much over there. Smugmug is good if you want it to be semi-independent for a photo portfolio or something, know a few friends who use it.