Ive played both games and i must say i enjoyed both, Doom was a bit scaryer imo but it is kind of an horror fps while F.E.A.R is more of an action fps with strong horror elements... Both are good games but IMO F.E.A.R is a little better, it did not revolutionize the gender but it polished it alot and did infact introduce some very cool elements (even if slow mo has been used in other games they do not come close to how it is used in F.E.A.R ,also ithas the best feeling weapons ive found in a Fps ever..etc.)
Another reason i think F.E.A.R is a better game is that my brother who refuses to play any fps games (and always has) has played , finished and enjoyed F.E.A.R. Thats like a vegetarian eating meat to be honest :D. Bottom line : None of the two games is truley revolutionary but both have revolutionary elements (in different areas) , my personal preference goes to F.E.A.R
Note: i have not mentioned graphics at all since i consider those just the skin of a game, although ifi would have Doom probably would have gotten a little ahead in that department.