I was just at a huge family gathering where I had at least 10 or so family and friends discussing GOAT's/Sports for a couple of hours. Home now and here's my takes on this:
Baseball - My choice was Willie Mays, I took him over Babe Ruth. Here's why - African Americans weren't allowed to play in Ruth's days, he didn't play against the best competition IMO. So I took a player Post WW2/Jackie Robinson Merger (1947-present). Mays almost hit as many HR's as Ruth did, Mays 660/Ruth 714. Mays also had a great career Batting Average at .302 and won 12 Gold Gloves! He also won a WS, so he is a Champion. He has the complete resume in a much better era than what Ruth played.
Football - My choice was Tom Brady , I took him over Joe Montana and Peyton Manning. IMO it has to be a QB because that is the most important position on the field. Don't give me Jerry Rice, dude was a WR. Brady not only has the most SB wins with 5 but has Great Statistics to go along with his Championships. By my eye test Montana was the most Clutch though by going 4-0 in SB's with 0 INT's in those 4 SB's = 4 legit Championships where he didn't mess up once. Peyton was a Coach on the field and won 5 League MVP's. Also he is the only QB in NFL History to win a SB with 2 different teams as a Starter, he does have 2 Championships which is nothing to sneeze at! This was close. I am still not real happy deep down with choosing Brady because of the Patriots cheating scandals = Spygate and Deflatagte, thinking should this be factored in when ranking him?
Basketball - My choice was Michael Jordan, I took him over Magic Johnson. Jordan won 6 Championships(6-0 in Finals), 6 Finals MVP's, and 5 League MVP's. He also won 10 Scoring Titles + won a DPOY award as well in 1988. Just cant top that IMO. Magic Johnson was a clear 2nd to me! Over 10,000 Assists in just 12 seasons, 9 Finals Appearances, and won 5 Championships. He to me was the best Leader in NBA history and clearly Greatest PG ever.
Golf - My choice was Jack Nicklaus. Sorry Tiger, you were on your way but have stunk up the joint for the last 8 years and Jack has you in majors 18-14 = edge has to be Jack without debate.
Boxing - My choice was Muhammed Ali. IMO I find it hard to believe anyone could beat Mike Tyson in the history of Boxing when Mike fought between 1986-1989 but longevity is a huge part of being great as well. Ali's longevity is just much better and it allowed Ali to fight and beat great fighters over 2 decades. He beat Liston in the 60s and then beat Frazier and Foreman in the 70s.
Hockey - I don't follow Hockey and rarely have watched it in my lifetime so no comment. Most people say Wayne Gretzky is the GOAT though. I know he had an amazing career but I also know there have been several other great players too.
Soccer - I don't follow Soccer and rarely have watched it in my lifetime so no comment. Most people say Pele or Messi is the GOAT. To be honest I have no fucking clue
Tennis - My choice was Roger Federer. He has won the most Majors with 18 so this was easy for me. He has won every Major at least once and has won Wimbledon a bunch.
Chess - It's Fucking Bobby Fischer! Drops mic, sorry Russia 3Peat out!