My favorit design's of Ash are Johto, Advanced Genaration, and diamond and pearl i dont realy have one favorit design of ash bc i like a few designs of him. And i really dont like the design of ash in the Best Wishes serie because he looks way much younger the before.
Advanced Generation (Hoenn/Kanto Battle Frontier)
Diamond & Pearl (Sinnoh)
Best Wishes (Unova)
I like the BW one cos it's bright and more colorful.