1. Answer: It depends on everyone's taste and these rankings change all the time. According to RankMyPorn, at the moment, the top ranked Straight Male Pornstars in the world are: Alex Legend, Bambino, Bruce Venture, Chad White, Chris Diamond, Damon Dice, Seth Gamble, Johnny Sins, JMac, Alex Jones, but these will change based on what people vote.
2. Answer: It changes. You can see the latest rankings on RankMyPorn.com and also vote on it for free.