Nearly all
Nearly all, the majority, the lion's share, the preponderance, almost all, the bulk, and the mass.
Numerous
Numerous, a lot of, great quantities of, countless, scores of, droves of, a horde of, a multiplicity of, numberless, untold, various, diverse, multifarious, abundant, an abundance of, frequent, umpteen, loads of, stacks of, heaps of, bags of, oodles of, hundreds of, millions of, zillions of, a slew of, bazillions of, a swag of, divers, a great/good deal of, a large/great number of, plenty of, innumerable, crowds of, an army of, a multitude of, multitudinous, multiple, several, sundry, assorted, copious, profuse, a profusion of, lots of, eleventy, masses of, scads of, piles of, tons of, dozens of, thousands of, billions of, shedload, gazillions of, gobs of, and myriad.
Greatly
Greatly, a great deal, exceedingly, appreciably, indeed, to a great extent/degree, a lot, considerably, and decidedly.
Often
Often, many times, repeatedly, regularly, customarily, usually, commonly, for a long time, frequently, on many/numerous occasions, recurrently, habitually, routinely, normally, for long, and a lot.
Example Sentences of Most
She is the most talented artist.
This book is the most interesting.
Most students prefer group projects today.
He has the most impressive collection.