Montiel park is a tough-ish little 9 hole. The course is wide open but has elevation changes. The course on campus at cal state san marcos is fun as well. The front nine are fairly long and the back nine are shorter which play through the campus. If you do plan on playing cal state san Marcos during the week, you should try to play it later in the day (less students) or on a weekend. Also, about 9 holes at CSUSM are lighted for some night golf. These two courses are about 6 minutes from each other and about 15 minutes from kit carson. Both are free as well (as long as you park on the street and not on the cal state campus).
IMO, morley is probably the most fun course in san Diego and kit carson is the most challenging.
Shoot me a pm and hopefully we can set something up.