-- the universe won't wait for you
Dub for everything before Best Wishes, sub for everything after. That's really only because that's how I started watching them. Originally I just saw Pokémon on TV so I got the 4Kids dub and then just stuck with it on rewatches cause I'm used to it. And when I eventually play catchup with BF & DP I'll watch the dub just cause I'll be too lazy to find subs.
But with Best Wishes, I started with subs and I'll stick with subs. I have seen the dub for most of it because that's what I watched on my catch-up watchthrough and occasionally I have to watch it to make a thread and have legit commentary. But I don't enjoy it as much. The dialogue is weird and the acting tends to be stilted and they've lost a LOT of Cilan's character in translation. Everything sounds more appealing in Japanese.
Actually, I guess... I started with Japanese raws and I'll stick with them? I hardly ever watch subs anymore because I watch the raw and have to wait over a month for subs so I just watch, get the gist of it, then watch tumblr for some summaries from people who understand more Japanese than I do. But yeah, no BW dub for me thanks.