Legal way to watch most of the anime without English subs (as it's the English dub!):
http://www.pokemon.com/us/tv-episodes/pokemon-episodes/
Might not have the episode you're looking, though. If you want to start from the very beginning, the site is probably 2 months from cycling back to the beginning of Kanto for the Kanto episodes (which includes the Orange Islands arc). Looks like the first episode of the Johto saga is up this week, though, as are the first few episodes of the DP/Sinnoh saga. Hoenn is probably 2 to 4 weeks away from cycling back to the beginning.