I just always was a good natured guy, I could never do the "evil" choices. I was pretty much pure paragon in both games. I guess you could say my Shepard was a like a boy scout.
Pure Paragon very much is a "boy scout," definitely, but I don't see Renegade as "evil."
Paragon and Renegade really couldn't have been better choices of terms for the "morality" paths. Well, Vigilante could have worked in addition to Renegade, but Vigilante does have other connotations that don't quite apply.
I remember going pure Paragon with my first character ever. I generally do that. My first KotOR character was, of course, pure Light Side. Then, like Erz posted, I had fun with a subsequent Dark Side playthrough to let loose.
What a player finds acceptable is a funny thing. Lots of people feel guilty being a jerk or evil, unable to find for themselves a disconnect with the game atmosphere (which generally speaks much about the immersion factor). Heck, even though I've found a disconnect when it comes to my characters, and can RP them as they should be to mold the story perfectly for them, I still don't like being a *****e toward the surrounding cast. Except for the peripheral ones. I'll leave holes in their skulls.
But my MainShep, she isn't Pure Renegade, but she's mostly Renegade. This is really only because a few Renegade responses here and there really don't make sense, or are stupidly written. There're a lot of corpses left in her wake, including the majority of colonists on Feros and Wrex, bwahahaha.