Considering opening repertoire

Mmmmm Pentaquark1. I recommend you English (1.c4) and Dutch (1...f5) against 1.d4. Sicilian Najdorf seems to be good.

I agree. The first opening I've studied for white was Queens Gambit (1. d4 d5 2. c4) but i recently switched to English, cause it often ends up with same/similar position to QG, but opponents are much less comfortable with it. Also, as being black you play Sicilian, if someone responds to English with 1. ... e5, then you can play Sicilian with reversed colours, which can be really fun, cause you're a move up and you can choose a variant.

If you're a casual player, then Sicilian may not be a good option for you. The Sicilian Defense is notorious for having to learn tons of theory if you don't want to get caught out in the opening. I personally prefer rarer openings, that do not require lots of theory and where my opponent is likely to be in the dark (like I am! :-))
Therefore, I play 1.f4 as White and the Benko's Gambit as Black.