WLP002/WY1968 is a really outstanding yeast strain and is probably overlooked by some brewers due to the diacetyl warning and the absurdly low attenuation listed on the yeast companies' websites. IME, the diacetyl production isn't all that severe (better than most lager strains, anyway), and if you follow the homebrewers' British Ale rule of thumb by giving it an extra few days at ambient after it looks finished, the diacetyl will be pretty much cleaned up. Cold crashing too quickly will give you yeast that poops out on you with almost any beer. In the case of 002/1968, that does mean diacetyl. I have never had detectable diacetyl from 002/1968, and I ferment them cool (63-65º F), but I do ramp it up as krausen begins to shrink. That said, if you are trying to get diactyl production (why?), then the thing to do is to use ringwood (005/1187) and cold crash as soon as the yeast drops.
I am also going to plug a couple other yeast strains. I like 1318 a lot because it is basically 002 with less fruit (therefore great for American-style ales as well as bitters and porters and whatnot). And S-04 is also a great and underrated yeast strain. I think people who don't like S-04 ferment too warm with it. I find it produces excellent beers anywhere from 60º F to 68º F, but it gets a little breadier at the cooler end (58º-62º F) and can be a little too ester-forward warmer than about 66º-68º F. My usual fermentation plan with that one is to pitch at 62º and keep the fermentation chamber set to 58º to get fermentation in the 64º-66º F "sweet spot." I know most homebrewers in my clubs tend to ferment most of their beers 4º-6º warmer than I do, and many still just use the ambient temperature of their closets (not a lot of basements here in Oakland). That may cause much of the discomfort some people have with S-04.