Kanada-Ya makes the most consistently excellent bowl of tonkotsu ramen anywhere in London. They've got four spots around central and north London now, but there's still always a line of students from Hong Kong and Japan outside any of their shops (even in the cold—usually a good sign), but it’s absolutely worth the wait. With the totally reasonable prices (just over a tenner for the basic bowl of noodles), it’s a good deal. There’s not a whole lot for vegetarians, so don’t bring them with the hope that there’ll be a veg stock or tofu option. Do go for a casual, no-reservations spot where the atmosphere is full of the sounds of conversation and people slurping noodles. Expect not to linger, but to leave happy.