1.big=massive(large in size, quantity, or extent), colossal(use this word, you emphasize somethings large), tremendous(INFORMAL)
2.avoid=shun(if someone shuns something, s/he deliberately avoid that something or keep away from it.)
3.fair=impartial(someone who is impartial is able to give a fair opinion or decision on something.)
4.attack=assault (physically attack someone), assail (attack violently)
5.dislike=abhor(abhor means you hate something to a extreme extent for moral reasons), loathe(dislike very much)
6.ruin=devastate (it means damage something very badly, or utterly destroy it.)
7.always=invariably(the same as always, but better than always)
8.forever=perpetual(a perpetual state never changes), immutable(something immutable will never change or be changed)
9.surprise=startle(it means surprise you slightly), astound(surprise you to a large degree),astonish(the same as astound)
10.enthusiasm=zeal (a great enthusiasm), fervency (sincere and enthusiasm)
11.quiet=tranquil(calm and peaceful), serene(calm and quiet)
12.expensive=exorbitant(it means too expensive that it should be)
13.luxurious=lavish(impressive and very expensive), sumptuous(grand and very expensive)
14.boring=tedious(if you describe something tedious, you mean it is boring and frustrating)
15.respect=esteem(if you esteem someone, you respect and admire him/her. FORMAL)
16.worry=fret(if you fret about something, you worry about it)
17.cold=chilly(unpleasantly cold), icy(extremely cold)
18.hot=boiling(very hot)
19.dangerous=perilous(very dangerous, hazardous(dangerous, especially to peoples safety and health)
20.nowadays=currently