UCSC offers four different introductory calculus sequences: Math 11AB, 19AB, 20AB, and AMS 11AB. Each sequence is designed to best meet the needs of a particular group of students. Be sure to enroll in a course or sequence that will satisfy your major requirement and serve as a prerequisite for mroe advanced courses you'll take! 

Math 11AB is designed primarily for students majoring in the life sciences. Most of the examples are from biology, and techniques that are likely to be useful to biologists are emphasized. 

Math 11AB isn't easier or less advanced than Math 19AB; it just has a different emphasis. If you intend to major in biology, you should probably take Math 11AB, even if you place into the 400 or 500 math placement tier. 

Textbook: Biocalculus: Calculus for Life Sciences, by James Stewart and Troy Day. If you click on "Look inside" on the publishers page, you'll find PDFs of the first four chapters of the text. The publisher's site also includes a complete table of contents.

Sample materials from Spring 2015: Syllabus, lecture notes, practice questions for the final, and a sample final.

Math 19AB provides a solid introduction to calculus, designed for students in the physical sciences, engineering, and mathematics. Many of the examples are drawn from physics, particularly classical mechanics. 

There are two versions of Math 19A and B: online and traditional "on ground" lecture/section formats. Typically, the fall and spring offerings of Math 19A are online, and the winter offering is traditional lecture format.

Textbook:  Calculus: Early Transcendentals, Single Variable, by Jon Rogawski. 

Sample materials:  Course outline for the online version of Math 19A.  Webpage for the Winter 2016 traditional lecture offering, including lecture notes, old final exams, and solutions for the winter 2016 midterm.

AMS 11AB is designed specifically for students majoring in economics. Most of the examples are from economics and the socials sciences, and the courses cover techniques needed for quantitative studies of problems arising in economics. 

Textbook: Introductory Mathematical Analysis For Business, Economics , etc, by Haeussler, Paul and Wood.

Sample materials: Here are the  course page (including a link to the syllabus) and solutions to quizzes from the Winter 2015 offering of AMS 11A.

Honors calculus is a small (30-50 student) intense introduction to calculus. Mathematical rigor and conceptual understanding are central to this sequence, which is taught by Richard Mitchell. The course is intended for, but not restricted to, math majors—most students who take the sequence decide to major (or double-major) in math, even if that wasn't their original intention; Prof. Mitchell is an inspiring instructor, and the camaraderie that develops among the students is amazing. 

Honors calculus could be a good choice for you if you love math or logic, or have already taken a strong calculus course and want to dig deeper.