I bought these LEDs from deal extreme:
E27 7W 4000K 700lm 14-LED Warm White Light Bulb - Purple (AC 85~265V)
http://www.dx.com/p/152093
There might be even better models these days. I wouldn't buy anything less than 100 lumens per watt. Also, 4000K color temp is the one I like best. This model is hemisphere and the purple thingy is a heat sink, so I assume it has a long life span.