From here:
Over a 19-year international career, Wasim Akram took wickets all over the world, in Tests and ODIs, with a consistency that was mind-boggling
www.espncricinfo.com
Based on the below I would say Wasim was the best pacer, if not bowler, of the 90s, along with Ambrose.
"Akram's best years were about to come. In his first Test of 1990, against Australia in Melbourne, Akram took
11 for 160, and that haul triggered a sensational run that lasted through most of the next eight years. In 48 Tests from 1990 to the end of 1997, Akram averaged five wickets per match, and his average dropped to an outstanding 20.05, before his form finally tapered off in his last four years.
During that eight-year period from 1990 to 1997, Akram had the best figures in Test cricket, barring none. There were several legendary bowlers who were at the height of their craft during an era which we now look back on as a golden one for bowlers, especially the fast ones - Curtly Ambrose, Allan Donald, Waqar Younis and Glenn McGrath were all around, but Akram's stats stood out even among them. His average of 20.05 was better than anyone else's during this period (with a cut-off of 150 wickets); in terms of strike rate, only Waqar was ahead."