I often like to follow a strategy across a roulette as well - in 425s (seemingly defunct), I was going to send only bands I've never sent before.
In the end, I always send something I absolutely love, but do also somewhat balance it with what I do know about the host's tastes. For instance, in the religion round here, I'm not going to send an artist (that is fairly well adored here) who is renowned for some serious religious leanings in their music. I know better.
What’s interesting is that the people that generally finish low score wise often account for the handful or more memorable songs sent post roulette. In other words someone could have very mediocre results in 7 of the 8 rounds but for one round, they’ll send a song long remembered as opposed to the roulette leaders.
Except Puppies. When he sends crap, he commits!