This is sort of like asking "What's your favorite screwdriver"? Depends what you're trying to do...no way would I try to make a weizen with 1968, even though I really like 1968 and use it a lot.
That said:
Bitters of any variety, oatmeal and sweet stouts - 1968/002
Light lagers/German pils - 2124/800
German wheat beers - 3068/300
Cream ale - 009
Maltier lagers (dunkel/bocks/ambers) - 833
Dry stout, porters, and English IPA - 1028
Tripels - 3787
Belgian Pale - 1762
Scottish ales and holiday spice beer- 1728
Meads - 71B
In general I try to keep the ale yeasts, on the cool side, 63-65 or so, for the bulk of fermentation. Belgians I might have a degree or two warmer, but no more, because I don't want rocket fuel. Lager yeasts I try to keep around 50 and then raise up to about 60-65 as fermentation subsides. It is possible to get lager yeasts fermenting too cold. One batch turned out full of sulfur because we hit a really cold snap and my garage stayed in the upper 30s for a week. That lager fermented at 43 and it was so slow the sulfur never offgassed.
As a general practice I pitch about 120% of what Mr. Malty suggests, sometimes even more. I give every beer at least 60 seconds with an oxygen wand, with the regulator cracked open just enough to let bubbles flow, but not enough to cause foam to spout out of the carboy.
3068/300 is best pitched at 58F, and fermented at 62F, to balance out the banana and clove. It won't attenuate all the way that cold, so you need to raise it up to about 68 at the end. I suspect pitching rate has something to do with the banana/clove ratio as well but haven't done any tests.
If you give 1968 enough oxygen, and pitch enough of it, you can get better than 80% apparent attenutation, even though the manufacturer lists it as much lower.
Sometime I'm going to try a cream ale with Cooper's dry yeast since it's supposedly the same strain and 009 only comes out once a year.
I set out running but I take my time.