Crowning Moment of Funny: After a Pizza-eating contest with MVP, he ate two slices while MVP ate none. Cue Matt blowing chunks all over him while he complains.
Hollywood Pudgy: Matt is quite possibly the best-known male example. He's constantly made fun of for his weight gain (especially with Scott Steiner quotes). Even dropping the weight hasn't stopped the criticism.
In one vlog he explains that his weight gain was due to digestive problems, and has gone on many diets to drop the weight. The diets all included grapes.
To be fair, one vlog showed Matt working out fairly hard (one might consider it a little too hard), and stating he would be on a diet guaranteed to help him in weight loss, and then showed up in TNA just as pudgy as before, if not worse. It's not hard to see why Matt is picked on for this after that.
Never Live It Down: When it was discovered that his girlfriend Lita was cheating on him with friend and frequent on-screen foe Edge, Matt had something of a meltdown and got fired by talking about the affair publicly. Since then, Matt's been stuck with the stigma as the guy who Lita cheated on and never got over it. More recently, he hasn't been able to live down being the guy WWE released for being fat.
If the Youtube suicide hoax doesn't become this, fans really are fickle.
What an Idiot!: Matt makes his WWE return in 2005, with the fans fully behind him following the Edge / Lita affair leading to Matt being released... And then Matt remarks in a promo that he wants them to die in a car crash, and the crowd died within seconds.