A very good combo i have noticed is devolution
spray or Mew's devolution beam with Dark Dragonite and Dark Slowbro.
1. Devolution Spray(Mew)+Dark Dragonite
This
takes advantage of Dark Dragonite's power to grab basics from the deck once
played. Use spray or Devolution beam to recall him back to your hand and call
out more basics.
2.Devolution Spray(Mew)+Dark Slowbro
This takes advantage of Dark
Slowbro's ability to retrieve KOed pokemon from the discard pile. Use spray or
devolution beam to pull him back then play him again to retrieve those much
needed evolutions or essential basics back to your hand.