Glen Park is near a bart station and has a small but reasonably entertaining center with restaurants, a small (high end) grocery store, and a couple of coffee shops/bars. You're also a very short hop from the mission (fairly cheap cab ride, 5 mins in the car). The nice thing is that it is extremely easy to get downtown on Bart (10-15min), but you're also in the southern half of the city near the freeway - so if you need to get to silicon valley, you don't have to battle city traffic.
Another cheaper option along the same lines is to live near Balboa Park - there's a bart station, a few good muni corridor lines. Transportation-wise, it's similar to Glen Park - quick strike to the peninsula, quick bart ride to downtown/berkeley. On the down side, this section is on the outer edge of San Francisco's rougher neighborhoods. But rents here will be lower.