It's on my "to buy" list along with Kerbal Space Program, I'll wait since I got an enormous Backlog of Games to play through

Braid has not been mentioned enough times in this thread.

And I'm I the first to mention Don't Starve??

Easily Journey. But if that doesn't count, Guacamelee and Mutant Blobs attack on psvita (didn't enjoy the ps3 version; I think platformers work much better on a small screen).

The ones I've played that I really liked are:

Bit.Trip Runner 2
Ittle Dew
Guacamelee
To the Moon
McPixel
The Stanley Parable (Pretty short, but I loved the narrator)
Amnesia: The Dark Descent (Does that even count as indie?)

And of course, the best indie game I have ever played hasn't released yet, so I need to play it first to be able to say that ;)

EDIT: I still need to play Shovel Knight.. also, Disco Dodgeball is pretty good too.

Dead Nation

Its not indie. But the only ''arcade'' games I liked are Geometry Wars and Shadow Complex.

I still need to play games like Shovel Knight, Volgarr the Viking, Gone Home, and Brothers. I have several of them in my Steam collection.

As a rogue like, Smash TV clone, or a mixture of the two, it's a bland and boring game with nothing going for it but t he art style, something too many indie developers try to push.  

http://gamrconnect.vgchartz.com/post.php?id=6818438 

(Talking about Binding of Issac)

The hitboxes are strange (instead of just being the physical size of the object, they try to give it some depth which just feels weird), the enemies are bland, the bosses are about as generic as possible, the shooting controls are loose, the game looks and feels exceedingly amateur...It easily gets outdone by almost any other modern game featuring permadeath and randomization (Rogue Legacy, Risk of Rain, Spelunky, FTL, Teleglitch...).

I'll give it that it is big, but I don't even consider that to be a good thing. With games like this with permadeath and randomization, your progression in the game isn't marked by how far you get, it is marked by knowledge and with so many items, you can't really be expected to learn it all (or at least without a grotesque amount of time) which holds back the feeling of progression.

Additionally, the game is one that gives you very little health and therefore very low room for mistake, but then it makes the controls and hitboxes loose and uncomfortable? Look at spelunky if you want to see a game that gives you very little health but does it right. The controls are super tight and everything in the game works the way you would expect, and it gives you things to learn on every run...

EDIT: Love you kupo :P

Cave Story was damn awesome.
Minecraft was pretty cool as well.
Oh, and that imaginary game that I want to make in the future :P