I'm in the same position. I actually decided to learn Rust (
http://rust-lang.org), which is a compiled language not unlike C. It's relatively new (version 0.9).
The main reason I enjoy it is that it forces me to think about problems in a different way than I'm used to. Rust is a typed language (with some type inference going on), and it doesn't really have arrays like PHP does, so it's a real challenge to solve problems in it.
For instance, I've been going through Rosetta Code (http://www.rosettacode.org) and trying to implement anything that sounds interesting in Rust. So far, I've done levenshtein (built into PHP), lzw compression, fibonacci sequence, MD5 hashing (built into PHP), quick sort, bubble sort, binary search, binary trees, etc. It's a lot of reinventing the wheel, but it's made me think about programming differently.
An example of a real-world result is that in my day job, I have an app that processes 10,000 items in 5 minutes. It takes that long for various reasons, but I decided to re-implement it in Rust. Using the exact same algorithm, Rust completed the task in 60 seconds -- that's 5x faster! But while I was working on it in Rust, I realized that I was doing some things inefficiently, so I reworked the algorithm in Rust. Once I completed that, the entire task took 250ms (!!!). I decided to port that algorithm to PHP, and my new version completed 10,000 items in 1.4 seconds.
Going from 312s down to 1.4s is a huge deal, and while the new algorithm doesn't solve all the edge cases that the old one does, it's good enough that I can use it and compensate for the differences later. I can process those 10,000 items in 1.4s, and then spend 30 seconds handling the 300 that the algorithm didn't catch.
Anyway, I digressed a bit, but I picked Rust, and I don't regret it. I suspect I would have had similar successes had I used C or C++ or Java, too.