One-on-one fights can be fun, but what if you don't want a whole episode or scene dedicated to just one person showing off? That's how you get Goku doing the same Kamehameha for three episodes. Sometimes what you want isn't a tight focus on a couple of characters, it's a melee that brings in a full cast. Another thing that great anime fight scenes need are high stakes. While a fight to the death isn't the only way to make viewers care about the outcome, it's a pretty effective method.
Sometimes the most exciting thing is a straight up battle royale in which a huge group of characters get in on the fight. This can occur in a single arc or even an episode, as it does in Naruto and Kino's Journey, but it can also take up the entirety of the plot, as it does in Future Diary and Deadman Wonderland.
Which are the best battle royale anime? That's up to you.
Each version of the Fate series differs in its content and themes, but one thing they most have in common is the epic showdown that is the Holy Grail War. Whoever gets their hands on the grail can have any wish granted, but getting there will require doing battle with a plethora of incredible weapons, including one sword so powerful that they literally created the earth. Plenty of blood will be shed in pursuit of the grail, but who will emerge victorious?
In yet another anime where the virtual meets reality, Ryouta Sakamoto is forced to play a real-life version of a video game - and that means fighting for his life against a group of fellow players. most of whom are pretty unhinged. Oh, and all of them have a healthy supply of grenades, which they've been commanded to use to kill seven of their fellow players. Should Ryouta fail to take out seven opponents, he'll be stranded on the island for the rest of his life - either that, or he'll be killed by another bloodthirsty player.
When Kirito is recruited into solving a mystery behind real world deaths that are apparently linked to deaths in the MMO Gun Gale Online, he winds up roped into a potentially deadly virtual free-for-all called Bullet of Bullets, where everyone has guns, and he has a glorified lightsaber. Luckily he has a talented sniper and experienced GGO player named Sinon on his side, and together the two of them wipe the floor with the competition - but not before getting some important intel for Kirito's investigation.
Not every part of Hunter x Hunter focuses on a battle royale, but the fourth stage of the Hunter Exam serves as a thrilling exception. Gon and the other participants are let loose on an island, where their job is to take possession of each other's badges. This wouldn't necessarily be a death match, except for the presence of Hisoka, a kill-happy clown who uses the competition as an opportunity to lay waste to as many people as he possibly can. What keeps Gon alive is less his battle skills than his strategic abilities, but it's still pretty gratifying to watch him come out on top with the help of his trusty fishing pole.