I agree with you. LG is terrible. Sony makes a weird looking phone IMHO and nobody even knows what that Nexus line is yet except for us hardcore geeks. It should stay with the top manufacturer so Google can focus on one device.
Here are my opinions:
SAMSUNG - This is the most likely manufacturers whether it's one or three or five. And it makes sense. But, I'm not convinced Samsung will be able to deliver a device with premium materials and builds. It could be just a spec-bumped Galaxy Nexus, or something very similar to the GSIII but with a bit of a curve that they've been known to do for the Nexus line. If they went with Samsung, I wouldn't be unhappy per se, but really hoping for Samsung to deliver more in terms of build quality.
LG - I'm willing to give LG a chance, honestly. What I've seen of the LG Optimus G is nothing but impressive. It really seems like they're trying. Plus, their display technology, and the fact that they're willing to make a unibody, non-removable battery enclosure gives me hope for better build materials, which I think the Nexus line is ready to have. I'm wary of LG, but if it's not going to be Samsung, I think LG is the only one I'd be willing to accept and keep an open mind about. The potential here is massive.
MOTOROLA - Dear god no. They make, hands down, the ugliest devices. I don't much care for Kevlar either, nor am I thrilled about a full-screen, bezel-less device. The one and only thing I appreciate from Motorola is their propensity to put large batteries into their devices. There's nothing else I care about from them. Plus, did I mention how ugly their devices are?
SONY - Also a no, but less so than Motorola. I too think they make awkward and pretty ugly devices. To have the device curve inward on the back... that just doesn't make sense to me for ergonomics. Also, I hate how they have that aesthetic line across the bottom near their capacitive buttons. Their Xperia line has gone down the tubes too, which makes me wary.
HTC - These guys are a hit or miss. I'm 50/50 about them. On one hand, they make decent looking devices (I actually think the HTC One X is overrated, a bit ugly and clunky looking) and have great displays. On the other hand, their insistence on putting the power/sleep button on top annoys me to no end. It makes the device horrible to use, reaching so far up for that power/sleep button. It's a deal breaker, in my opinion. Plus, nearly every device they've put out has had battery horror stories, so I just don't trust them anymore.
I'm also open to a few wild cards like ASUS. That'd be hella interesting.
TL;DR:
-Most okay with Samsung.
-Willing to give LG a chance
-Big NO to Motorola
-Less of a no to Sony
-HTC... eh, 50/50.
-ASUS... surprise me!