5. 1973 Philadelphia 76ers (9-73)
This team is defined by its losing streaks as the '73 76ers had losing stretches of 13, 14, 15, and one horrendous run of 20 straight games without a win.
4. 1942 Detroit Lions (0-11)
The '42 Detroit Lions were just awful. They showed an utter lack of competitive fire as evidenced by only scoring 38 points for the entire season. To add insult to injury, they were shutout five times.
3. 1899 Cleveland Spiders (20-134)
I don't normally dip this far into the past as I like to keep things somewhat current but this team was so bad that they couldn't even get teams to come play them. They had only 42 home games as they couldn't generate enough fan interest to warrant other teams to travel there. This resulted in the Spiders setting an unbreakable record of 101 road losses.
2. 1976 Tampa Bay Buccaneers (0-14)
The first season for this franchise, the '76 Bucs were the first NFL team to go an entire 14 game season without tying or winning. The tone for the season was set in the opening game as they spent 20 minutes trying to find their way onto the field, getting lost within the Houston Astrodome.
1. 2008 Detroit Lions (0-16)
I almost feel bad for putting this team at number one on this list because they were really competitive in stretches and despite their winless record, wasn't the worst team in the league (I felt). But a record setting 0-16 in America's number one sport means you get to go down as the worst sports team ever. Sorry.