Surprisingly, when I think of my favorite ramen in Tokyo, of course the famous ones like Jangara in Harajuku and Tsukumo in Ebisu come to mind, but I actually really like the shio ramen at Koumen, at least the branch in Ebisu. That's despite (obviously) being a huge tonkotsu fan. For shoyu ramen there's a place in Nishi-Shinjuku called Musashi that I liked quite a bit, but I don't eat shoyu ramen very often. I honestly haven't had a great miso ramen, but that's probably because I don't seek it out.
In the US, the list of edible (ok that's an exaggeration) ramen drops dramatically to pretty much just one -- Setagaya ramen which just opened up here in NYC in the East Village. I haven't been to Momofuku, as it doesn't to seem particularly authentic so it doesn't have that much of an appeal to me. After that, I suppose Minca is edible, but just avoid the cha shu, which just tastes like pure black carbon. I guess some people seem to think the ramen at Sapporo or Menkuitei or Ajisen are real ramen, but they aren't really. They wouldn't serve ramen that bad at the worst truck stop in Japan (slight exaggeration... well, maybe not).
Other than that, I can't say I've had decent ramen much else here in the States. I suppose there's Sapporo and Tampopo in San Francisco, but again, these places are like Sapporo or Menkuitei here in New York. Well Tampopo isn't terrible, but it's just not that good...
I think I'd rather have a good bowl of Goota or other fancy instant ramen that eating at most of these places. But unfortunately you can't get Goota here in the States. Someone linked a picture above to a nissin miso ramen that looked like it might be good.
Other than that, call me simple -- I like the Nissin Cup O' Noodle. Sapporo ichi-ban kitsune instant ramen isn't bad. Nong Shim Kimchee Bowl Ramen is a classic for the Korean stuff...
Man, now I'm seriously craving a bowl of ramen...
Best,
-Jason