Unique place that is, as Steve said, a little off the beaten path. Pat O'Malley's Jet Room is a pretty no-frills breakfast place (they offer lunch as well) serving up some good diner grub. Bonus feature: You can watch planes take off and land while you're chowin' down.
Out of all the diners in Madison that I've been to, the Jet Room service is the best; seriously top-notch. Pat or his wife have been hosting every time I've gone (and have even remembered my name when I went a couple weekends in a row), the staff are friendly and always on top of things. I get a pretty good mom 'n pop type vibe from here.
I've never had a problem with the food here. It's solid diner food; nothing unexpected or that exciting, but always delicious. I like it enough that it's one of the few places where I'll try to switch my order every time I head over there.
Waits are long on weekends, so call ahead or expect to spend some time looking around the building.