Welcome to the club. Raikou's a great choice, one of the best Electric-types ever. He eluded me in my Crystal game. I had him weakened enough and he still got away.
I feel sorry for you. I battled a Suicune on Silver exactly when I didn't want to see it, so I sent an Ultra Ball flying without even doing anything to it when I thought I was pressing the Run option. The Run Option probably wouldn't have worked anyway - Although my highest level Pokémon was above 40, I was training my Eevee at the time which was just Level 23. As expected, it fled after that turn. In fact, I heard that in HG/SS, if you put a Legendary Dog to sleep, it can still run away.
Column #1: I like Mow Rotom better, mainly because it's not a Legendary.
Column #2: Chinchou's cute enough to have my vote.
Column #3: I like Magnemite better because it gives Special Attack EVs. They could also do good on your party when you've trained them.
Thundurus? Yeah, I don't think I like it that much.
Column #4: Stunfisk, because Stunfisk. Stunfisk said.
Column #5: Luxray's awesomeness will never fail to have my vote. :) I always have one in my Platinum Team. Also, I've already given a Rotom form a vote, so it'd be unfair for the other Pokémon to not have a vote.