Small colleges don't offer as many majors as big colleges; however, some of them let you design your own.
Courses at small colleges are usually taught by professors, not teaching assistants. The professors may even know your name and areas of interest.
Be aware that small colleges do not have the research facilities of large universities. If you're hoping to be a research assistant, find out what kind of work and facilities are available before you apply.
Although you'll find a robust social life at most small colleges, you'll find less in terms of big sporting events and variety. However, there is often a stronger sense of community and connection.