Aika offers a very hearty tsukemen, with probably the thickest and strongest-taste broth I have had in a long while, if ever. The shop is interesting and "cozy", with two guys and a lot of steamy pots boiling. The steam condensed and droplets ran down the big glass picture windows in the cold winter weather. They have 7 chairs and one small table for two. They have both lunch and evening menus - they are both pasted on the window outside so make sure that you are looking at the correct one. There's no ticket machine. You get a tsukemen bowl full of onions and pork, and a broth that is almost like a stew - the onions are interesting since are a combination of both the chopped tama negis and the stringy type. The noodles were well-cooked, slightly thick, and had nori on top of them. Now this place is about 15-20 mins walk from JR Hachioji station, and while you walk through the shopping district (the diagonal street that runs northwest from the station), you can see a number of good ramen places. They have a ranking of 66 on Supleks - very popular and well-regarded - but there was no line (although the shop was full). If you want a full meal you might want to get the omori size though, the default noodle amount was only 200 grams.
Ramen Livedoor Page
Diddlefinger Map (English labels)