What internships did you take that you would suggest to undergrad students?

I did my education in India before moving to Austin.

I did 4 internships in 4 different type of organisations - 1 was a new startup that needed a graphic designer and were glad to have me as an intern, another was a 5-10 yr old small size firm that exposed me to actually working in an electrical appliances factory, the 3rd was a multinational firm where i was part of electrical design team for buildings (datacenters, hotels, etc) adn the 4th was an internship in an accounting function of a fortune 500 company.

Each taught me something new. Diversify your interets, team sizes, company sizes, experiences. Internship essentially means that you get to try. Go ahead and do exactly that. Try new experiences.

Focus on interning at a place that provides you experience in your career choice. Also find an intern in companies you are interested in working in after graduation.

These are a bit outside the normal biology-related ones, but some of the national labs run by the US Department of Energy and others (Fermilab, Argonne, Brookhaven, Sandia, Livermore, SLAC, etc.), not to mention NASA sites across the nation (Ames, Johnson, Kennedy, Wallops, Lewis, Marshall, etc.), have internships for undergrads. There are few places in the world with a bigger "wow" factor, and some of them actually do have bio-related programs too. (For example, NASA does xenobiology, and I'm pretty sure some of the national labs have biomedical arms, e.g., associated with synchrotron radiation sources.)

AT&T Bell Labs also had internships (and presumably still does); even though I did one as a grad student, I'm pretty sure there were a number of undergrads there in the same program. (This particular case probably doesn't have many bio-related options, though.)

And while I'm not personally familiar with them, I'd bet the National Institutes of Health in Bethesda and the CDC in Atlanta also have internships.