Parenting is a perfect example where you need to practice satisficing (being good enough) rather than maximizing (being perfect). (For a lengthier discussion of satisficing versus maximizing, see "The Paradox of Choice")
Some people consider me an "admirable" father because I work sane hours, handle all the transportation for the kids, do most of the cooking, and shun business travel* as if it were a contract with the Devil.
*Side note: I have a lot of friends who are extremely successful in business and are fathers. They feel the strain of trying to balance constant travel with being a dad. One recently commented to me about the subject, "I feel like the proverbial frog in the slowly boiling pot. It didn't seem so bad when I first started, but now I'm definitely getting cooked." I would argue that constant business travel is one of the most stressful thing for dads. For more on this, you can check out my post on being a global business leader:
Yet does that make me a good father? I could do all those things, and still be a lousy father who constantly berated his kids and put them down. (I'm not saying that I am--obviously I try to give them unconditional love--I'm just making a point).
Ultimately, I think you judge parenting by asking yourself three simple yes or no questions:
1) Am I a non-abusive parent? That is, do I avoid verbally or physically abusing my children?
2) Do I give my kids unconditional love in a way that they recognize? That is, if someone asks them if Daddy loves them, do they unhesitatingly and joyfully answer yes?
3) Are all of us (including my wife and kids, not just me) happy with the way our family runs? Because it the end, it doesn't matter if I think I have the perfect life if the other people who share it are miserable.
If you answer "Yes" to all three of those questions, consider yourself a good parent AND STOP COMPARING YOURSELF TO OTHERS. The time you spend worrying about your parenting would be better spent playing with your kids.