What is the best gauge of speaker wire for home theater speakers?

Gauge of wire depends on the Impedance of your speakers and the length of the run... here is a chart that describes what is needed...I like to use 16 gauge for front speakers and 14 gauge for rear... Wire size 2 Ω load 4 Ω load 6 Ω load 8 Ω load 22 AWG (0.326 mm2) 3 ft (0.9 m) 6 ft (1.8 m) 9 ft (2.7 m) 12 ft (3.6 m) 20 AWG (0.518 mm2) 5 ft (1.5 m) 10 ft (3 m) 15 ft (4.5 m) 20 ft (6 m) 18 AWG (0.823 mm2) 8 ft (2.4 m) 16 ft (4.9 m) 24 ft (7.3 m) 32 ft (9.7 m) 16 AWG (1.31 mm2) 12 ft (3.6 m) 24 ft (7.3 m) 36 ft (11 m) 48 ft (15 m) 14 AWG (2.08 mm2) 20 ft (6.1 m) 40 ft (12 m) 60 ft (18 m)* 80 ft (24 m)* 12 AWG (3.31 mm2) 30 ft (9.1 m) 60 ft (18 m)* 90 ft (27 m)* 120 ft (36 m)* 10 AWG (5.26 mm2) 50 ft (15 m) 100 ft (30 m)* 150 ft (46 m)* 200 ft (61 m)*

12 14 or 16 doesn't really matter, i like 14, works good in banana clips

for most systems I use 16 gauge wire unless you have long runs then go to 14