Originally Posted by darthbimmer

We need more information to make a recommendation. The best choice in mode of transportation depends on exactly where you want to go (ie, you're planning to visit more than just the airport grounds, train station, or bus terminal, right?), where you're starting from, how much time you have, how much you're willing to spend, and whether you'll want to have a car when you get there.

For example, I've gone between LA and SD at various times by airplane, bus, and one-way rental car depending on the factors I mentioned above. FYI buses run about $25 OW and are the cheapest option short of hitch-hiking.