City of Heroes/City of Villains.
Free 14 day trials.
Incredible costume choices. At 1st level. Capes? That's level 20. 95% of everything else? You got it now.
Wide-ranging difficulty settings. From pretty easy to ridiculously hard. Change 'em as often as you like for no cost. Think you can take on a x8 spawn at +4 levels?
Immersive back-story. Multiple threads, multiple secrets and reveals. WHY are the Clockwork robots vulnerable to psychic damage?
Large, established, FRIENDLY playerbase. Forum regulars COMPETE to answer questions first, and accurately!
Mission Architect: Make your own mission and story arc. (Not on trial, sorry!). Make your own enemies and allies. Put yourself in!
No "holy trinity" of tank/healer/dps required. Make your team, run with it. Warning! May require adjustment of tactics. You know... thought?
95% of content is solo-able. Where exceptional challenges are going to show, or multiple persons are required, you will be warned.
Travel powers and zone teleporters allow you to get into the action fast. No need to jog through the jungle for 20 minutes to get to a mission. Friendly veterans may buy you a jet pack, which you can use at 1st level. Get one for yourself at level 5 through the Safeguard/Mayhem mission. Get a permanent travel power at 14. Or not. Up to you!
95% mission instances mean no spawn camping required. It's your mission. Just you and whoever you decided to team with can access it.
No "add-ons" required. The interface is complete as is. Although, www.paragonwiki.com is a great resource.
Archetypes (classes) are wide ranging, and can have very different playstyles, even within the archetype. Force-field defenders are very different from Radiation Defenders which are different from Kinetic Defenders which are different from Empathy Defenders. Cookie-cutter builds are around, but are not required. Do it your way!
"Supersidekicking" means a level 10, 20, 30, 40, 50 can go into the level 30's mission OR the level 10's OR the level 50s, and ALL will be challenged and rewarded! Play with your friends and form a team, no matter the level!
Invention system means crafting new power for your character. Or temporary powers. Or costume items. Or temporary buffs. Or respecs. Or play the market for the heck of it!
Casual friendly. Log in, knock out a mission in 20 minutes or less. Or form for the 2-4hrs task forces/ strike forces. Heck, with team agreement, you don't even have to finish those in one sitting!
All in one box. Free trial. Architect Edition $20 gets you your first month, and a bonus package. (I suggest the Magic Package. THe costume pieces are snazzy, and the Fortune power is useful on teams. The Robot package does have some cool techno-pieces, and the Self-Destruct power is fun, although somewhat... limited.)
I'm with the Mentor Project, the goal of which is to help newer players get the most out of their time in the City. PM me if you are interested.
EDIT: On Skype, I hear my buddies groaning over "grinding for X" in other games. I find it very odd. I play for fun!
There is "endgame content", but City Of is "all game content". Have fun and fight crime (or commit it!) whatever your level.