I suspect it's a combination of things. Penny and Bernie are prettier/sexier, and I think looks are a big deal to Raj. But beyond that, her personality is less intense/interesting/exciting, so I just don't think she gets men's attention the way the other two do. However, Amy's personality was probably the most consistent with what Raj wanted. He was clingy and commitment-minded, and she was kind of that way, too- both with her friends and with Sheldon.

Maybe the best answer is because Raj doesn't know what's good for him? Or because he realizes that clingy is not very attractive although he's unable to stop being that way? Or maybe he doesn't like long skirts and hair barrettes.

@wonder2wonder said:

Raj dreams about Bernadette and he and Penny woke up together in the same bed, naked.

Hower, Raj has never been attracted to Amy. Why not? What is wrong with him, or with Amy?

"The heart wants what it wants or doesn't."

Amy just wasn't that girl you turn around to watch walk down the street. At that time (pre-Lucy) Raj was all about looks…something Amy never played up.

Trust me, if Amy had shorten those skirts, dipped the top of those blouses, put on enough makeup to rival a Kardashian, and found her way to a hair salon, Raj would have been all over her.

There was that time on the "Girl's Night Out" with Raj along too, where he said about Amy (something like) "Okay, I'm in love with you too."

@wonder2wonder said:

Raj dreams about Bernadette and he and Penny woke up together in the same bed, naked.

Hower, Raj has never been attracted to Amy. Why not? What is wrong with him, or with Amy?

"The heart wants what it wants or doesn't."

You missed the rest of that scene https://youtu.be/VMiA5po2Keo

@znexyish That's him just making excuses afterwards. The crux of the matter is that Raj doesn't look at Amy the same way as he does at Penny or Bernadette.

@wonder2wonder You're right. Raj was caught and he was just finding a way out. He finds Amy too plain for his taste.

Maybe he'd be more interested after her Nobel Prize make-over?

Here's what I meant:

Part 1: https://www.youtube.com/watch?v=NiJWKl2EUqQ

Part 2: https://www.youtube.com/watch?v=Vn-9BULXPvM

Stuart was interested in Amy. She also looked pretty as snow white and as a Starfleet doctor.

So was Bert.

There is nothing wrong with either Raj or Amy not being attracted to one another. They just aren't. They like each other but that's all that I can see. Plus Amy is not going to put up with any of that kama sutra crap he might want to pull on her.

Well let's be fair. Raj said he doesn't actually know any of that stuff, he just says that to women to impress them.

@Knixon

That was meant to refer to a line from Penny after their almost night together. When they meet afterwords to discuss what happened she says: "Oh God did you pull some weird Indian crap on me"

On a side note, when I searched for the line using "Kama sutra" or "Indian crap" I came across two articles on how "racist" the show was.

Yes I remember that. But Raj did say he didn't actually know that stuff.

All Raj needs is his "Beyonce Bootylicious Dance Mix" tape to get the party started.