Product availability is really changing fast. Last fall's offerings at Sam's Club and Costco no longer exist. So if you need LED lighting right now, the optimum solution is at Home Depot, "while suppplies last":
HD Online LED bulb This bulb is bright enough at 428 lumens, but a little pricey at $20. But it's by far the best value as all the other LED bulbs that are this bright will set you back $30-$70 each. And get this, it's guaranteed to last for 46 years (vs 7 for CFLs). Other important features are that it reaches full brightness immediately (unlike CFLs) and is dimmable (rare for CFLs).
I have decided to concentrate on standard medium base screw in bulbs, since they will fit the most economical and the most common fixtures.