My favorite is to do incline hammer curls to failure (6-8 reps.) then jump up immediately and bang out reps to failure of standing dum. curls with the same dumbells. Kills my bis!!
my favorite are one-arm preacher curls. if u do them correctly they will really develop lower portion of bicep. I also like the hammer curl because it builds the outer head of the bicep and it also has secondary forearm advantages