Taking this team by team from the list given from my mind which is bored on a Saturday morning:
Cowboys: They have been like this for a while. Total Jekyll and Hyde team. This should not surprise anyone. They have been doing that for years. Just when you think you can trust Romo, he throws 5 picks on a Monday night. Then, as soon as you write him off, he throws for 4 TDs. Defense seems to be fairly consistent, but overall, I wouldn't pick the Cowboys or anyone they are playing against in a survivor pool. I would have more confidence calling the coin flip at the beginning. (I hear people bet on that) Final thought: Saying they are the biggest mess is reactionary from a bad Monday night game, but with an owner who can't stay out of the media and off the damn TV screen, they are second in the race for biggest clown team.
Raiders: I don't know what everyone expected from them at the beginning of the year. They have a new head coach and a below average QB (yes, I'm a Bengals fan). Their WRs are inconsistent at best, if not totally inexperienced and their defense has no way to stop the pass. DMac looks slow this year to me, and with O-line unable to open any holes, that is a huge problem. The play calling has been as vanilla as the preseason, and they aren't getting their best player involved in the passing game. The Raiders are at least 2 years away from being anything worth a crap. They need a real QB, at least one good receiver, two DBs and well, a whole new team. Maybe they can move to LA. That always works. Final thought: The are fairly inept, but not clownish. At least they beat the Squealers.
Panthers: Cam overhype was prevalent in the preseason. He will be a good QB, but he still has to have people around him to make some plays and at least a passable defense. The defense is not even average and the players around him are, with the exception of Smith, just not that good. Three RBs is a mess and the best of the three to compliment Cam can't stay on the field. Smith is old by NFL standards. I am sure a full page ad in the paper promising a Super Bowl win sounded good at the time, but other than that, this team hasn't done anything "clownish". Final thought: Cam is a competitor. All these guys are. He sulks when he gets pulled, but it was the right move. They were down by a bunch and no reason to risk getting him hurt. Not even close to a clown team.
Cleveland: As a Bengals fan, I actually feel sorry for the Browns. I feel the pain of years of ineptitude and we are still looking to get over the hump. I don't see ANYTHING in their makeup that would say they are a clown team. They have a bright future in my opinion. They have a lot of talent on this team. Haden is going to be coming back week 6, and that will help what has been a pretty solid Defense. The offense has shown signs of life, but lets face it, the Browns have had one of the toughest opening schedules in the NFL. I don't see them beating the Giants this week, but I wouldn't be surprised if they get their first win against my Bengals week 6. They play tough. Final thought: No where close to a clown team. They are not a good team, but there is no circus here.
J-E-T-S suck suck suck. So, this wasn't a worst team question, or a 2-2 team wouldn't even be in the mix. But as far as clownish, well, the Jets are a joke. This is the biggest circus in the league. There is a reason the mouth breathers at ESPN keep talking about them... they think people care. Other than Pittsburgh, they are the team I love to hate the most, and quite frankly, this year they are pulling ahead of Pittsburgh on my hate list as the Squealers are about to be irrelevant (my opinion) for a few years. Final thought: The Jets need to just move to the arena league and play their home games under a big top. Seriously, I don't think its possible for me to dislike a coach more than I dislike Rex Ryan.
WINNER: Jets by a landslide, but dishonorable mention to the Cowboys