http://www.flickr.com there are others but i like flickr the best http://photobucket.com/ and there's this too http://www.23hq.com/
I use www.fotki.com It's very easy to use and navigate which is great for me since I have a ton of family looking at baby photos. I'm thinking of starting up a flickr site also though.
You're going to have to create an account at any sharing site, so does it matter which? The one thing I like about flickr unfortunately didn't work for this particular site here. That is posting html code because flickr allows you to easily copy/paste code that will display a smaller image that is clickable to the larger image. So far, all the other sharing sites I've checked out you would have to either know the code yourself or upload a smaller image in the first place (nothing more annoying than people who post larger than 800x600 images in forums since many still run 1024x768 desktop resolutions.) I don't like the way flickr is organized. It has a bit too much and I prefer to have the viewed image in the main focus with a sidebar of your other images for easy access to viewing. More like a galery is what I like, but I haven't found a sharing site that is like that. Any I've seen has been more personal websites than sharing sites. Photobucket only allows 1 mb files with the free account. Flickr allows any size, but only displays up to 1024x768 according to the rules, but some of my non-4:3 ratio photos are shown larger than 1024x768.
I think that's 1 gig... That works out to around a thousand photos. What you might consider doing is opening an account on both sites. Upload some pics, get a feel for each, and then decide. All it costs is a little time.
