It really depends on what department you're talking about. The biology and physics departments are wonderful, and there's a good selection of classes as well as research labs to choose from. With the upcoming merge of Robert Wood Johnson and Rutgers New Brunswick, this will open up even more opportunities for undergraduate research. However, the chemistry department is probably one of the worst. They have no regard for the academic well-being of the student and many of the professors are simply horrible at teaching. When you take into fact that pre-meds have to take General Chemistry and Organic Chemistry, this can lead to disaster if you're not prepared to deal with it. In the case of Organic Chemistry, it is not uncommon for the exam averages to be around the low 60 and high 50s area. Most of the professors in the department are either old or foreign.
Another problem is the university's poor judgement in terms of allocation of funds. Most of the funding goes to the football team, which is to the detriment of the students. Since Rutgers can't buy more intercampus buses, the buses tend to become VERY overcrowded during class changing times and it literally is a fight to see who can get on the bus first. Also, even many upper level science classes are large (Systems Physiology, Fund of Neurobio, etc.) where it is next to impossible to get to know your professor. This can make getting LORs very hard. Last but not least the university can't seem to maintain its facilities because of funding issues. The bathrooms in some of the buildings on College Ave are simply atrocious and it wll feel like you're walking into a landfill once you enter.
So as you can see Rutgers is a mixed bag. You can make the best of it if you try. If you want an institution with a huge social life that has a decent science program, this is the place for you. However do not pass up a university like NYU, Penn State, etc. for Rutgers since they will take care of you better there.