Personnaly, I go for something like that:
font-size: 81.25%; /* 62.5% -> 1em = 10px / 75% -> 1em = 12px */
font: 13px/1.615385 Verdana, Helvetica, Arial, sans-serif;
Then I use ems for each different element:
It gives the same size of text in every browser. And it's easy to modify if needed.