The first season English opening is a classic. I daresay it's one of the best anime openings of all time, and a strong contender for the very best dub opening for an anime, like no dub opening ever was.
I'm also partial to Spurt, which was one of the Japanese openings during the Battle Frontier saga, if only for the nostalgic value.
I claim to be the official Porygon2 of the Pokemon Black 2 board. Scientist MileRun: WaRy associate