How tough is it to get into a good college, such as Tufts, Holy Cross, Boston College, Georgetown, etc?

I am a junior in a public high school in the Boston suburbs, and I make mostly As and very few high Bs in my courses. I take all the accelerated courses so far, and my unweighted gpa is 3.8 right now (with the addition of the accelerated courses). I am on the track team, and I do significant community service and am involved in the national honor society. My colleges I am interested in are Tufts, College of the Holy Cross, Boston College, Georgetown, Brown, Northwestern. Any advice, suggestions?