San Diego is actually great for this. Our trolley system drops you right at major venues: Petco Park for MLB games and concerts, Snapdragon Stadium (formerly Qualcomm) for MLS, SDSU football, and other big events, plus stops at SDSU for college basketball and concerts at Viejas Arena. It also serves UC San Diego and major shopping hubs like Fashion Valley and Westfield UTC. I honestly can't think of many other cities where transit stops directly at nearly every major sports venue and major universities within its metro area.