City of Heroes is going Free-to-Play later this year.  However, the free version has a limited set of features compared to the full version.  For example, you don't get as many archetypes to build your character, you can't "whisper" to other players (meaning to talk, you have to stand next to each other), and you are limited to 2 characters.  You can see the rest of the limitations here: http://www.cityofheroes.com/news/freedom/player_choices.html#tabs-4
I know I'll try and recreate Jon Thunder at least.  
Source: http://ca.kotaku.com/5814214/you-dont-have-to-pay-for-city-of-heroes-anymore-thanks-to-freedom

It's too bad you can't get your original character back.. I know it was a long, arduous battle getting Gia Earthshaker up to whatever level she was at... I did the first 30 or so solo, which looking back was pointlessly difficult... Perhaps I might rebuild Petr Grim though.. we'll have to see.  Let me know if/when you hear it is going live, I did love that game...

Age of Conan is going Free-to-Play as well!  http://kotaku.com/5817365/now-age-of-conan-is-free+to+play

And World of Warcraft's free trial is no longer 10 or 14 days, it's as long as it takes you to reach level 20.  (Of course, level 20 is when you earn mounts and often cool powers).

Diddlycraft of course remains free for life.