I tried a cheese slice at Tel Aviv Kosher Pizza last night (6349 N. California). Not bad at all. The slice itself was thin and foldable, served the proper way ("to go" on a paper plate for street munching), and the crust was thin, hot and crispy on the edges and soggy in the middle, just like any self-respecting New York slice. Cheese and sauce were balanced and tasty. Size-wise, it was a little small, but the price was right ($1.70).
[note: Tel Aviv also serves Kosher "Mexican" and "Chinese" food as well as other Italian standards and the classic tuna melt. The proprietor is very jolly and regaled us with entire segments of dialogue from his favorite movie, The Pink Panther.]
Speaking of New York slices, I had one that very closely approximated the real thing, grease-wise, just the other day at Santullo's (in the Flatiron Building at 1943 W. North Avenue). Again, I tried a cheese slice to go. This one was enormous and eminently foldable, thanks to an undercooked crust, and it was the oiliest thing I've seen in a long time. Orange grease ran in tributaries down the slice, into the bag, and onto the sidewalk. My dog began speaking in tongues when she got a whiff of it, so after I had a couple of bites, it was all hers.