Formal:
* Il est magnifique. (This is the most direct and common translation.)
* Il est grandiose. (Emphasizes the impressive scale or grandeur.)
* Il est splendide. (Emphasizes the beauty and brilliance.)
Informal:
* Il est génial! (This is a more casual way to say "he's awesome!")
* Il est super! (Similar to "he's great!")
Literary:
* Il est majestueux. (This emphasizes the regal or majestic nature of the subject.)
* Il est admirable. (This emphasizes the subject's worthiness of admiration.)
The best choice will depend on the specific situation and the tone you want to convey.