i live in n new york. i have an evo mini, a fahgettaboutit U, and a new york noose chain. i like to collect locks and mix it up a bit. i have found that the evo mini is most useful, and i will use it unless i will be parked for more than 2 or 3 hours. if i will be parking in mahattan for more than a few hours i use the F-U. i really trust the FU. holy smokes that thing is a brute, and is not to be trifled with. do not taunt the FU.
unfortunately the evo u will not fit on a parking meter. of course you will find enough signs.
the chain is cool as well, because it can be locked to weirder things, like park benches and such. the noose is wildly superior to the normal chain.
but if i had to have just one lock i would have the evo mini, unless my bike was really expensive, then i would go with the FU.
also i use a locking skewer up front, i think that is worth it. cant use the locking skewer on the back of course, the fixed wheel has the other kind of axle.
i also emailed kryptonite and they keyed my locks alike, which is nice.