Out of all the free clicker games on Steam, I'd have to say
Tap Tap Infinity is the best. It's got a cute, Square-Enix look to it, and there's just enough story there to keep you interested. The EXP-based skills are nice, and there's an ability that advances you to bosses automatically. There's no pay-wall to worry about since you'll have more than enough of everything, except stars, to boost your recruits. Some achievements are virtually impossible to get, though.
Clicker Heroes is decent, but it's missing quite a bit of power-ups and replayability. Those rubies are few and far between, so I'd say there's a pay-wall there in terms of gilding your heroes. Clans are a little foolish, and the relics suck. They don't even auto-level.
Time Clickers isn't bad, but there's no story or point to it. Takes forever to unlock some things. Like, seriously forever. Some of the last power-ups require 11,000,000 cubes, and even at maximum cube gaining you'd be lucky to get 700,000 by level 4925 which is the infinite health/end level where you have to restart. That's
way too much grinding for nothing.
AdVenture Capitalist is pretty funny and I enjoyed playing it; it's just missing things to do after you unlock The Moon, where it becomes incredibly grindy. Even if you speed up the game 100x, it still takes forever to get Angels. Definite pay-wall. It also eats up a lot of computer resources, too.
Sakura Clicker is great for
the weeaboos, but doesn't have achievements and requires paying to unlock trading cards. Blah. These monster girls obviously have psoriasis with all those red splotches on their breasts.
Crusaders of the Lost Idols is the newest one that I've been trying out. It's rich in story, as opposed to most clicker games with no story, and it has some nice features like team orientation bonuses and various missions to unlock rewards. The biggest problem with the game is no auto-forward option, so you'd have to script a mouse to click on loot chests then click on the advance arrow button.
And yes, I use speed hacks at 100x speed so I don't have to waste too much time on each one. I've found that Crusaders of the Lost Idols is a real bitch when you speed hack it, though; it connects to the server to auto-save your progress after a certain number of minutes, so 100x speed yields constant time-out errors. 15x speed is optimal.