I've been told alot that I have great calves (perhaps is just genetic though). But then again I do live in cattle country...ha ha.
What I've done for my calves is progressivly heavier routines on seated calf raises and standing calf raises. I do seated one week, standing the next, and continue to alternate. My pattern believe it or not is a BFL routine of 15, 12, 10, 8, 6, then 15. I start with 90lbs on the 15 reps, and add a 45 plate for each new set. I end with 6 45 plates on the seated. Then I go back to the original 2 plates (90 lbs) and do 15.
If I can actually stand after that, I've failed that day.
It really has improved my size.
HOWEVER, here is my "big secret" for calves. DO NOT neglect the front part of the calf muscle (on the front outside part of the shin). You work these by standing on your heels and raising and lowering your toes. If you build a solid Tibialis anterior, and soleus muscle, your calves will look much much larger despite not adding a whole lot on the backside (gastrocnemius).
I see it much like a shoulder issue. If you're not building your posterior delts in combo with your anteriors, and lats, your gonna have shoulders like a girl (sure it looks good when your FACING the mirror). Same goes for calves. You'd be surprised just how well your Tibialis anteriors respond to some directed excersises.
At least all that is my experience anyway.