I have trouble comparing parts of Kill Bill because tonally each half feels differently. I like the second part greatly, it just feels different. The elle/bea fight is one of my favorites too, it's just very different than the Crazy 88 / garden fight, and there's more focus on the backstory and contemplation, less cutting/action overall. (Put another way, part 1 feels hopped up on coke, part 2 is like having taken a downer and is contemplative overall.) And technically it's a continuation, not a sequel.
Never saw the original jumanji. Saw the recent one...fluff, but enjoyable while it lasted. I think it will be more interesting to compare ITS sequel arriving soon, since it's a true tonal sequel to Welcome to the Jungle.
It's kind of a lost cause to get into an argument about which of two great movies that are actually somewhat different styles and genres are better than the other.
Usually sequels suck, so the gist is simply that Aliens is not a sequel that sucked.