3. The Denver Broncos "polo" jerseys
Back in the 2012 offseason, Nike acquired the rights to outfit the NFL. Previously, it had been Reebok outfitting the NFL, and even though we're more than 10 years removed from that, it's kind of insane to think about given how badly Nike dwarfs Reebok as an overall company in the sports fashion market.
Needless to say, Nike's brand combined with the NFL was an exciting time for people who care about the fashion of the NFL, but the unfortunate reality is that Nike seems to have done more harm to the NFL than good. They have had some absolutely horrendous uniform re-designs under Nike, but one of the Big Swoosh's first orders of business upon acquiring the rights to outfit the NFL was apparently to make every team look like they were wearing polo t-shirts up top.
It's still hard to believe they did this. I don't know that any NFL team still has this, but Nike's decision to take half of the collar away and make it look like a polo t-shirt is one of the most egregious mistakes this company has made in the last 10-plus years, and it looks even worse in hindsight.
If you think about it, Nike's decision to cut the collars in half really served as an omen for what was to come from the company as they took over the primary rights to NFL uniforms. Thank goodness they realized this error quickly and just moved to GIANT collars in the 2013 season, although some teams were stuck with the polo-style collars for a few years.
That collar looks like the bottom half of the fancy letter "S" you used to draw when you were bored in class. If you know, you know.