Handy website:
http://pokemongo.gamepress.gg/pokemon/149So on defense, there are undoubtedly useful movesets (slower the better, and lower dodge window the better).
On attack, however, a lot of skills are pretty equal. Here's why (and let's compare dragon claw and dragon pulse).
Dragon claw at face value looks like it's strictly better. It does 27.34 dps and costs 50 energy, whereas dragon pulse does 22.57 dps and costs 50 energy.
Here's what people are forgetting in calculations: Dragon pulse does 22.57 dps for 3.6 seconds for 50 energy. Dragon pulse will keep you doing high dps for longer, before having to switch back to dragon breath which has only 15 dps.
So let's do the math:
Dragon breath + dragon pulse: Approx 7 seconds of dragon breath charges 100 energy. So, dragon pulse does 7 x15dps = 105 damage while charging to full energy. Once at full energy, 3.6 seconds x 22.57 dps x 2 releases = 162 damage. The total is 267 damage over 14.2 seconds (or 18.8 dps).
Dragon breath + dragon claw: Same calculations, 7x15 = 105. Once full energy, 1.6s x 27.34dps x2 releases = 87.48 damage. The total is 192.48 damage over 10.2 seconds (or 18.87 dps).