worthwhile

valuable, worthy

big, consequential, earthshaking, earth-shattering, eventful, historic, important, major, material, meaningful, momentous, monumental, much, significant, substantial, tectonic, weighty

decisive, fatal, fateful, strategic

earnest, grave, heavy, serious, sincere

distinctive, exceptional, impressive, outstanding, prominent, remarkable

distinguished, eminent, great, illustrious, noble, notable, noteworthy, outstanding, preeminent, prestigious

famous, notorious, renowned

all-important, central, critical, crucial, essential, key, pivotal, seminal, vital