Lemonstein said:

I agree with Captain Antilles and add to that...

Darth Hade said:

Luke is surprised/shocked to see Vader, but we all know he shouldn' be since he saw exactly what he wanted to see. Making it look more in line with what I would would call a "dream-like" sequence would have been a better choice...

That's totally wrong. At no point is it said that Luke is in control of what he "takes with him" into the cave. I think you're missing the very point of what the cave test is for. It manifests the subconscious, it's not a Holodeck.

Are you serious?

"That place... is strong with the dark side of the Force. A domain of evil it is... and you must go." - Yoda

"What's in there?" - Luke

"Only what you take with you." - Yoda

Luke wants to fight Vader. He wants revenge for what he believes to be the murder of his father. It doesn't matter what Yoda has said up to that point, Luke is about revenge.

He may not be entirely conscious of his feelings, but he wanted to see Vader in there.

That's what he wanted.

That's what he made happen.

That's what he got.