My favorites are;
Dr. Web Security Space (no bloat, extremely light battery use, full featured - clean and easy, STRONG Firewall)
Bullguard Mobile (Full Featured, very little bloat, incredible anti-theft/device control)
Norton (Good all around)
Depending on my licensing, I swap between all three of these but tend to lean toward Dr. Web Security Space because it has no measurable important on performance or battery and that firewall is really good.