Just my opinion, but I'd go Lebron over MJ with a title tonight. I believe the game of basketball has never been played at a higher level than this era. This era is absolutely loaded with superstars. Kareems era was filled with guys on drugs, unathletic guys that look like could be your plumber in 2020 rather than a basektball player. Not to take anything away from Kareem, he's a legend of course, but Lebron is gonna pass Kareem is essentially every statistic, and played in a much tougher era.
MJ obviously has the perfect 6-0 in the finals, but he also got knocked out early more than Lebron did. Combine that with the fact that the NBA had a big talent gap in the early 90's (expansion teams coming in, guys still not knowing how to handle their money) and I just think Lebron is better and had to overcome more. I also think Lebron beats MJ 1 on 1. He is bigger, faster, and stronger than MJ.
I do think Colin Cowherd said it best. Lebron is the greatest player to ever play the game of basketball. MJ had the best basketball career.
This argument will probably never end and I do think there is generational bias. Heck, I'm biased because Lebron is my generation. But I'm willing to bet that those that say anyone (other than MJ) is better than Lebron grew up in a different era and thus are much more passionate about that era.