Hmm...should I post here? No. But I shouldn't drink alcohol either.
This entire post is mainly aimed at you, Levi.
First of all, you came in here and said Roy was better than Marth, then asked us to prove you wrong. Appeal to ignorance. It's your job to give us premises to support your statement, not our's to refute your completely baseless one.
But, because I'm in a ranting mood, I'm going to slowly explain to you why Marth is better than Roy anyway.
There are many things Marth has over Roy, but one thing really seperates them in the tiers more than anything else. Marth has a tip sweetspot, while Roy has a tilt sweetspot. What does this mean? It means Roy has to get really close to his opponent to be effective in combat. Well, wait, doesn't that defeat the point of having a -sword- in the first place? Why yes, it does! Compare Marth/Roy's attack animations to, say, Fox's, and what do you notice? Fox's are generally much faster. The reason Marth and Roy's attacks are a bit more laggy than average is because their sword gives them reach. It's a basic compromise found in many games: more reach, more lag. The problem is, Roy gains that lag for nothing, since he's fighting within Fox's range anyway. Marth, on the other hand, can play a spacing game, since he wants his opponents at the outside of his reach, so his lag is justified.
I could also throw in that Roy is definitly NOT faster than Marth (this has been proven time and time again through frame data. It's not debatable), and Marth's attacks are actually slightly -stronger- than Roy's, assuming both are sweetspotted. Their swords are the same length, by the way, so don't bother bringing that up. Actually, due to something called the "Roy zone", Marth's is arguably longer.
Then there's their falling speeds. Marth is floaty, allowing him to chase opponents into the air and combo very fluidly, while Roy's fastish-fallerness prevents him from doing pretty much anything outside of dtilt -> uair.
I could go on, but I've satisfied my need to rant. Please don't be ignorant and try and refute this information, it's 100% fact by now.