Jesse James Garrett gave the closing plenary at IA Summit 2009, and he asked a question of the audience, name some great designers.
And the audience shouted out names.
Then he asked, name the works of design they are considered great for.
And the audience was silent.
...
Don't look for names. Look for works, and then find out who made them.
If you don't know what's considered good work, don't ask like you asked this question. "Good" is subjective, and design is not art; design has a purpose, is backed by research, has metrics, supports a business model. Rather, you want to study work that solves the problem the designer intended. Maybe they intended to make it easy to book an airline ticket, or maybe they intended to appease ten different executive vice presidents. Pick any work, and learn why it was made that way, and determine if it's great or not (or, more likely, if there are aspects which are great for a particular use case). You could do in-depth interviews, you could do contextual inquiry, you could ask the designer, you could usability test it, you could go through heuristics, you could do GOMS, there are any number of methods.
But don't look for names first.
