What are the best Web Galleries?

I am one of the few avid MobileMe users. I use the gallery and like it. Nice upload features, integration into iPhoto. Not perfect, but it does the work, plus I have lots of disk space. However, Apple makes the transition from MobileMe to iCloud. During this transition, several features of MobileMe will be dropped. Besides the very useful syncing of keychains between computers, the gallery will cease to function. Some strange photo stream service will be introduced, which does not seem to be a real gallery replacement, but more like a large cache of you last 1,000 pictures taken. Useful, but only to a limited extent. So what are my alternatives? I need (in order of importance):

• Share with other people (who are not signed in, a la Facebook)
• 5-10 GB space for pictures or more
• Able to make photo albums, user gets a nice web browser based viewer
• Option for users to download the photos
• Optional high resolution versions of photos (2048 pixels or more)
• Good integration with iPhone, iPhoto et al.

I would pay for that service, if it includes 10 GB space or more. 

I already found out that Flickr and Picasa Web offer unlimited space, but in the free version there are quite the restrictions (limited image resolution, image usage by hoster, limited number of photos that can be controlled, advertisements, ...). Plus for example the Picasa Web Uploader for the Mac is horribly outdated (iPhoto '08...?).

So what other options are there? Which one is the best?