Hard to choose just 5 but here is my pick:
Team Rocket is my favourite set so 3/5 of the arts are from there (the Vaporeon above is technically from Legendary Collection, i wish it was holo in Team Rocket too) Nidoking because the art is badass, Looks like he is about to go super saiyan. Jungle Jolteon because finding my old childhood one is what got me back into collecting 4 years a go 