Actually SC1 is the defacto choice when talking about StarCraft esports and the best choice since the best SC players have been honing their skills on SC1 for a long time (see South Korea SC1 esports scene).
There are actual professional players still active for SC2 though. I don't think you can make that claim for SC1 because even though the competitive scene has been growing again nobody is getting a paycheck for playing competitive games.
Are you referring to the just completed Afreeca Starleague with $21k prize pool? Only the top two got more than a typical month's paycheck (winner did get over $10k) and it lasted a couple of months. There also haven't been any other events even close to that size this year for BW. Pro players don't typically live off tournament winnings.
That's the one! The winner pulled in $13,500 USD. I must have misinterpreted "paycheck" in your comment "nobody is getting a paycheck for playing competitive games."
[edit] Ah, $21k, not $31k. Thanks.
[edit] And yes, it was recently completed and isn't actually ongoing. Not sure what I was smoking when I made so many false statements.
Yeah you could've well meant the VANT event, I forgot about Afreeca just announcing another large one. Who knows, with how things are going we might see professional play again in Brood War and of course some of the current players were at the top when it existed.
While there are currently no professional players, as amateurs, the top guys definitely earn more than what you would get as a professional SC2 player. In July 2016, the 10th highest earned $7,699.18 USD, the highest $36,811.18 USD. And those numbers don't include ad revenue, tournament winnings or sponsorship deals.
Earning through streaming can be detrimental to the level of play though. At least one of those top10 doesn't even bother playing competitive matches and I'm pretty sure he's not the only one that's not really a competitor even if he's making a living as an entertainer playing Starcraft.