One thing I never did learn was what went into the sauce for the noodles themselves. What I gathered through taste is that some combination of sesame/peanut paste, soy sauce, chili peppers, and vinegar. I'm sure there is more to it, but I foolishly never bothered to ask.
Here in NYC, I've only tried a few sesame noodles, but my favorite so far is from Mee Noodle Shop in Hell's Kitchen. They make it the closest to what I grew up eating, but as mentioned, it's nowhere near as good as what I remember.
Really what draws me to this dish is the intense sesame/peanut flavor that comes out mixed with the mild saltiness from the soy sauce. It's disappointing to me that there isn't as much flavor from Mee, but until I find something better, they curb my cravings.