In a shocking upset, it was revealed that my longtime favorite animal, the tiger, would by most reasoning LOSE to a lion in a fight. Apparently the tiger, supremely adapted to lone hunting, is an apprehensive fighter- the slightest injury could cause him to be unable to hunt effectivly and thus to starve. What's more, the tiger would most likely attack with a bite to the throat, the best method for asphyxiating natural tiger prey like giddy leaping deer and lost-in-the-woods human....However, the lion's mane has evolved precisely to PROTECT that very area(...as well as disguise his embarrassing pencil neck, haha you scrawny fuck!), so our sleek tiggy friend would likely end up only with a mouthful of fur. Finally, the lion, while a shitty hunter(and a sexist pig!), spends most of his non-sleeping time fending off challenges by other male lions, and is well versed in the dirty tactic of attacking the rear of the opponent front leg rather than going for the throat.....In the end analysis, the Don King of the animal world reigns supreme.
Of course both can be crushed in short order by a full-size grizzly....which, however, can't even manage to properly clean their own furry asses....
http://www.lairweb.org.nz/tiger/conflict.html