Positive:
* General: amazing, wonderful, fantastic, brilliant, superb, excellent, outstanding, exceptional, phenomenal, incredible, remarkable, extraordinary, marvelous, splendid, terrific, impressive, admirable, noteworthy, praiseworthy
* Intense: awesome, mind-blowing, awe-inspiring, breathtaking, spectacular, staggering, monumental, epic, legendary
* Intellectual: brilliant, ingenious, profound, insightful, astute, clever, smart, wise, perceptive
* Emotional: joyful, delightful, heartwarming, inspiring, moving, touching
* Physical: beautiful, stunning, gorgeous, magnificent, grand, impressive, majestic
* Quality: high-quality, top-notch, first-rate, first-class, premium, superior, impeccable, flawless
Informal:
* General: sweet, rad, cool, awesome, killer, sick, epic, dope
* Intense: badass, rocking, off-the-charts, mind-blowing, out of this world
Specific:
* Success: triumphant, victorious, successful, groundbreaking, innovative
* Power: mighty, powerful, strong, dominant
* Size: huge, massive, gigantic, colossal, vast
* Age: ancient, venerable, historic, classic
Other:
* Unique: unparalleled, unmatched, unrivaled, exceptional, extraordinary, one-of-a-kind
* Effortless: natural, effortless, seamless, smooth, easy
* Worthy: deserving, valuable, important, significant, meaningful
* Elevated: superior, refined, elegant, sophisticated, distinguished
* Opposite of bad: good, fine, decent, satisfactory
The best word to use depends on the specific context and the nuance you want to convey.