2) Bc4 in the Sicilian
1) e4 c5 2) Bc4 seems to be a very popular line on this website and is quite common in otb chess- at least among club players in the UK. Why? I suppose it looks aggressive, but a little experience proves that the Bishop just get chased around, thus helping Black's development. Black has been getting great results against 2) Bc4 so it should be welcomed by the second player but, personally, I find it very unpleasant to play against! That's not because I get bad results (+83% at the moment!) but simply that the positions that result are generally slow-moving and turgid. A big bore! To the White side it must just be depressing!
So my advice to anyone considering 2)Bc4 in the Sicilian: play almost anything else! You are much more likely to have fun and you will certainly experience greater success!