I think you have to go #2 behind MJ after adjusting for all the benefits modern day players have. Yes Russell and all the winning was huge but Lebron and the competition and consistency after all the pressures of modern day social media and 24/7 coverage?, epic.
I'm of two minds on MJ ranking one and LBJ second. MJ only entered the NBA at 21 years old (LBJ at 19yo) and missed out on nearly 4 full seasons due to retirement (came back for final 17 games in his first return). And even at 39 years old was still schooling players and averaging 20 a game.
Even with those missed seasons in his prime, MJ in his 15 seasons has numbers that best LeBron's 15 in scoring, steals and blocks. Let that sink in. Blocks for a shooting guard.
LBJ leads in assists and rebounds, and slightly ahead in shooting percentages but MJ was no slouch in all those categories.
By the end of LeBron's career, his numbers will far surpass MJ and he'll be in top 10 in a lot of all time categories. But if MJ had started earlier, played longer and didn't retire twice, I have no doubt he would also have some untouchable stats including all time leading scorer. That's just from a statistics perspective.
MJ was all about determination and the will to win games and he never had a terrible playoff series or game that lingered in people's minds or questioned his abilities. LBJ was once heavily criticised for shrinking in playoff games and clutch situations.
For the entire body of work that LBJ will one day finish with, I think I would rank him just that slightly higher than MJ. Just the numbers, year in, year out, and the ability to jump from one team to another and immediately bring them into serious contention for the championship.