Give me
George Mikan as my primary vote. Getting used to saying that, hoping this will be the last time.
It seems like it comes down to "era transportability" and how much of a determent you view his playing in the era he did as.
I like the argument that non of his peers have popped up yet and are unlikely to anytime soon. I tend to believe I view the pre-shot clock guys more favorable than most and even I have to admit I don't have Cousy until the thirties, Arizin and Schayes until the 40's and the other early NBA elites like Neil Johnston, Bill Sharman, Easy Ed and co. until after the century mark.
But we should note that it is just a eight year window from the dawn of the league until the retirement of Mikan and the age of the 24 second shot clock. Regardless, the only major objection I have to anyone who isn't voting for Mikan yet is if you're just ruling those guys out because of the era, and I think a few voters are. The project expressly states that these players are to be considered and if you haven't done your due diligence in terms of research, you're doing a disservice to the results.
A few things about Mikan that i feel are getting lost in the discussion and which actually bode well for him in terms of how he'd have fared in other eras.
1) Mikan was a superior athlete and a player of considerable all-around skill. He developed an ambidextrous hook shot, the preferred weapon at the time, had good ball handling and passing skills for a big man and was a near 80% foul shooter for his regular and postseason career, a feat today's big men still struggle to achieve. Here's a couple of early newspaper accounts detail Big George grace and dexterity despite his imposing frame.
"

And the great Joe Lapchick, former Original Cetlics and the first great Knicks coach opined as follows...

This is important because it shows a refinement of skill level and overall athleticism that relative to his era was perceived as exceptional. Mikan was not some lumbering oaf who simply out muscled and out-reached his pint-sized peers, he was exactly what we have come to find most great big men in NBA history to be, a much better athlete than people his size who developed an essential skill set.
2) He also was the type of ferocious competitor that we typically associate with the all-time greats. Mikan was such an ironman that he played with broken bones in all four of his limbs at some point in his career. And he would do anything to win. Red Auerbach began his coaching career against Mikan and remarked sometime in the 1970's "If he played in the NBA today or tomorrow he'd be a great player. He had the competitive drive to be a great player. He was a tough then and he'd be a tough guy now." A decade later he added, "That man would be a stickout anytime, anywhere, under any conditions."
3) We wasn't just a winner in the NBA. It's been noted that Mikan was also a star in the NBA for two franchises in his first two years and that he was a stud in college and that he was the dominant force in the only integrated elite pro basketball prior to 1950, the World Pro Basketball Tournament and exhibition games against the Harlem Globetrotters and New York Rens. Mikan earned the respect of opponents and fans of all races by playing his ass off and winning a whole lot. Here's former Rens coach Bob Douglass on Big George. "George (Mikan) was the reason we wanted to play them so badly. He was the best and we wanted to measure ourselves against the best. He gave us back everything we gave him...there was a lot of mutual respect and any bad blood had to do with wanting to win the game, not hurt the other man."
Alternate vote:
Bob PettitMore on him when I actually vote for him. But suffice to say he has the resume that needs to get recognition before much longer. Almost out of guys elite guys who won a ring as the clear cut best player and won at least one MVP. They need to be off the board before much longer or someone's got some spalnin' to do.