Wish Bliss is good, but I know it is very hard to come by on wifi. Softboiled works too, and is better against Gengar. I like Softboiled better overall because so many pokemon try to set up on Blissey, so it is good to heal Blissey quick instead of waiting two turns.
I would probably run Flamethrower/Stealth Rock/Softboiled/Seismic Toss or Thunder Wave.
Flamethrower is one of the main selling points of using Blissey in 5th gen, simply because Chansey cannot use it and Chansey competes with Blissey for a team slot. It also hits Scizor, Excadrill, Ferrothorn, and Forretress.
I would also run standard Skarmory with Spikes/Roost/Whirlwind/Brave Bird. Although however, you can drop Spikes for Stealth Rock for a second attack/support move on Blissey. Personal preference.