So I'm going to list the seasons of Death Battle and a generalization of my thoughts of outcome and fight quality, so we have a record of it in this thread, mainly because I've forgotten a few episodes even happened. I'll do Season 1 now and do some more later, I have some work to do.
-Boba Fett vs Samus Aran: Completely wrong, weak reasoning, started the whole thing off. Animation 4/10
-Akuma vs Shang Tsung: Correct then, correct now. Reasoning kind of made sense, even the "plot" of the fight did. Animation 6/10
-Rogue vs Wonder Woman: Really wrong, I don't even think Diana would notice Rogue stealing her power before she murdered her. Animation 5/10
-Goomba vs Koopa: Don't know, don't care, it was a joke. Animation 3/10
-Mike Haggar vs Zangief: These two are basically equal since they're in the same universe, so their idea that Zangief's experience would win him out makes sense (Mike's the mayor, not really a combatant anymore) Animation 7/10
-TMNT Battle Royale. Right outcome, reasoning was sound. Animation 6/10
-Zitz vs Leonardo: Stomp only because the 4Kids timeline existed at the time of the video. Animation 5/10
-Yoshi vs Riptor: Huuuuuge stomp, funny fight animation. Animation 4/10.
-Felicia vs Taokaka: Felicia doesn't have a page here, but based on how low Felicia is on the Darkstalker totem pole, I think the fight is correct. Animation 7/10
-Kratos vs Spawn: Considering at the time it would have been GoW3 Kratos vs Hell King Spawn, I'd say it was about right, but would have been a really long fight. Considering only holy weapon decapitation can kill Spawn and his suit feeds off Kratos' sins, he should be able to outlast him. Animation 2/10
-Bomberman vs Dig Dug: Extremely wrong, weak reasoning. Animation 3/10
-Vegeta vs Shadow: Once Shadow went Super, it would have been over. Animation 5/10
-Mario vs Sonic: Since it was composite and Galaxy wasn't a thing yet, it was correct at the time. Animation 6/10
-Luke Skywalker vs Harry Potter: Holy shit, what a stomp (even in the fight, Harry only hit Luke twice) Animation 6/10
-Chun-Li vs Mai Shiranui: Correct outcome, decent reasoning. Animation 7/10
-Starscream vs Rainbow Dash: We have two profiles for Starscream, none of which really matter for this fight, but she would still be stronger and faster than him since he's cannon fodder. ANimation 5/10
-Master Chief vs Doomguy: Halo 3 Chief vs Doomguy (not Doomslayer), yeah it would be close, but their reasons for Chief would be correct, since Doomguy's strategy basically makes him a Brute. Animation 6/10
-Dr. Eggman vs Dr. WIly: Bass would have murdered everyone before Metal could become Metal Overlord Animation 7/10
-Zelda vs Peach: Peach stomps hard, so they were right. Animation 5/10
-Thor vs Raiden: Even they recognized it was a stomp. Animation 6/10
-Link vs Cloud: They are probably correct, but their reasoning was super flimsy. Animation 6/10
-Batman vs Spider-Man: Considering it was a no prep-time fight, it was accurate. With prep, who knows? Animation 6/10
-Pikachu vs Blanka: They used anime Pikachu, so Blanka would be blitzed. Animation 3/10
-Goku vs Superman: With SSJ4, Superman would have been completely destroyed. Animation 8/10