spectacular
Very impressive, amazing, or exciting to see or experience.
Spectacular means impressively dramatic, striking, or amazing to see. When fireworks explode across the night sky in brilliant colors, that's a spectacular display. When a gymnast executes a perfect routine with difficult flips and perfect landings, the performance is spectacular.
The key idea is that spectacular things grab your attention and make you stop what you're doing to look. A spectacular sunset might paint the whole sky in vivid oranges and purples. A spectacular catch in baseball might have an outfielder leaping high against the fence to snag a ball that seemed destined to be a home run.
Spectacular implies something beyond just good or nice. A pretty flower is pleasant, but a whole meadow bursting with thousands of wildflowers of every color might be spectacular. A scary movie might be okay, but one with spectacular special effects creates scenes so realistic and thrilling that audiences gasp.
The word can describe failures too. A spectacular failure means something went wrong in a big, obvious, dramatic way, like a carefully built house of cards collapsing in slow motion, or a science experiment that was supposed to fizz gently but instead overflows.