[olympus]

I'll go ahead and suggest the obvious: Wordpress.

It has one of the largest ecosystems (if not the largest), and you can usually find multiple plugins to do whatever you want. You can self host, use their free hosting, or pay for their premium hosting. It has a variety of responsive themes (both free and paid), and a mobile switcher that will auto-detect if you are surfing from a mobile or desktop device. Due to its popularity there's tons of tutorials and help on bunches of forums. It may not be the best if you are looking for a particular feature set, but it is probably the best all-around solution.