Easily cryptokitties by far. They have gathered another 15 million dollars from the VC funding from big companies like google and Samsung and venrock just to get the game higher.
They are running out of the kitties they are basically selling but in reality they will still be making a lot of money if the activity in the game stays the same, right now their discord is so crowded that you can't really follow the messages. Since, the company is making money from the trades and sales of the kitties, as long as there is action going on they will keep making money.
From each sale of a kitty the company is taking 3.75% commissions, right now kitties do not worth a lot and most of them even worth less than the transaction fees and breeding fees etc so they are really cheap, when the prices start to go higher without new gen zero kitties printing than company will start to make even more. Just from the most expensive 10 kitties that was sold they have made over 10 thousand dollars.
Closer to 150 thousand dollars made from just the top 10 kitties, think about how much money they are making daily from all the transactions going on. Dapper Labs found an amazing idea, lets hope they will keep it going for a long time with this activity.
Yes, cryptokitties is the best one in my view too. Not because it is the best style of play or one of the best games out there but the reality is that if you want to check dapps, they are the highest paid most played game out there that has a direct blockchain linked to it.
Normally there are some games with blockchain traces but mainly done via some other engine as well, cryptokitties is pure blockchain all around and they had millions of dollars made thanks to it with a really high interest to it at its peak. Right now there are a lot of people playing it and a lot of money changing hands even though it is one of the worst times in its short history. Hence if you want to see the "best" dapps as in the most successful ones, cryptokitties is the one you are looking for.