Why is Roman Catholicism considered the epitome of Christianity?

I've been a Christian now for 12 years, grew up Southern Baptist and left that church when I got to high school because I saw how racist and hypocritical they could be. So I decided to become a Christian, simply Christian, which no affiliation with any other denomination because I see denominations as creating "cracks" between our fellow brothers and sisters in Christ. And people now ask what religion I am and I respond "Christian" and then ask "What kind" and expect I'm Catholic because of my belief in Christ.I'm sure many have pointed this out, but why should I be a Catholic to be a Christian in come one's eyes? No offense to my Catholic brothers and sisters: you're just as much of a believer as I am :) Thanks.