Love Sideswipe but gotta go with Screamer.
explanation:
If it was a episode of Deadliest Warrior, Starscream would probably win 700 out of 1000 battles. In any fight, when weapons into play you have to bring out all the factors on the table.
Weapons and Physical Features
Sideswipe in the movies is seen with only 2 weapons, his dual pistols and his dual Wolverine-style blades. On his bio, he is said to be the fastest of the autobots. He is a Lamborghini Countache.
Starscream is the fastest of the Decepticons. He is a F22 Raptor and possibly a better flyer than most human pilots. He has so many more tools and weapons. In addition he has long range capacity, something Sideswipe lacks entirely. If he catches Sideswipe in the open, it's almost a guarantee kill if Sideswipe tries to fight him head on. He is twice of Sideswipe's size and although he got his arm ripped off, he still stood against Optimus and survived, even hurting Optimus.
Xfactors
Sideswipe is master of all the Martial Arts on his planet. He is the most ferocious autobot and the one of the more courageous ones. In the video game, he is swatted aside by Megatron only to stand up and stab him in the foot eventually leading to his retreat.
Starscream was a military leader before the Autobot/Decepticon war started. He has so much more experience. Starscream, although cowardly, is also very cunning while Sideswipe is cocky and reckless. This can be exploited by Starscream. As seen in a comic book (i think), Sideswipe underestimates Starscream and gets "outwrestled." One would think that if Sideswipe got up close, he'd have the advantage.
In Conclusion.
Starscream has the better tools and the better Xfactors. He would emerge victorious most of the time. Although Sideswipe is capable of severly wounding bigger opponents he is unable to finish them, as shown in the Mexican Standoff. Also when he kills Sideways, most people don't know that Sideways was a cowardly scout sniper with no close combat experience. That is like Anderson Silva beating up a good fencer in the Octagon and then saying "Damn I'm good."
I'm pretty sure though, if Sideswipe didn't get cocky, he'd give Starscream a run for his money at close range. Also remember how cowardly Starscream is, he even tried running from Sam when he got the upperhand. If Sideswipe was getting the upperhand, he'd just fly away, turn, and bomb the place from 9000 ft.
hulk
the fallen
bumblebee jazz and optimus prime
the 7 godzillas
Whitebeard
It would be a very close match. Sideswipe is a very good warrior, and he has slightly more longer melee weapons, and that gives him the edge. However, Mirage is just as skilled in combat,and has the power to turn invisible. He also has two long melee weapons. But the power to turn invisible and the wits to outsmart any sensor gives Mirage the upper hand. It would be a very violent battle, but in the end, mirage would win. Mirage also uses guns, but sideswipe usually doesn't. Either Mirage would snipe Sideswipe, or pepper him with bullets. Mirage also has hookwhips, and that gives him a lot more weapons and choices, which would let Mirage win. Even in vehicular combat, Mirage has the edge, because, in my opinion, a ferrari is better than a stingray.
Lions vs African Buffalo 60% Lion would Win !! lion vs Elephant 80% Elephant Would Win Lion Vs Tiger ? Tiger would win 90% Rhinoserous vs Lion Very Difficult for Lion zebra vs Lion ? Lion would win 80% giraffe vs Lion Lion would win 70% of the Time
hulk would destroy all of them. so hulk would win.
hulk will win.
The Chupacabra would win.
The elephant would win.
Hulk would win.