I would look at the following factors when deciding between a small and large school:
1. Do you like the idea of personal attention from your professors or are you more comfortable being anonymous?
2. Does the small school have all the programs you might be interested in and are there any barriers to participating in a program? For example, many small schools have 3-2 engineering programs which mean that you would finish your degree at a different school.
3. Does the small school have all the extracurricular activities you might be interested in?
4. Does the large school have a smaller program, such as an honors college, that will enable you to have a more personal college experience.
I would be very careful, however, in basing your decision on the fact that you don't want to go to a school that is smaller than your high school. At your high school, you knew many people in your grade before you got there and moreover, you knew kids in the classes below and ahead of you. At college, you will know very few people when you arrive and each year a completely new group of students will matriculate. It will not feel the same as high school.