The transfer from Anaheim to downtown L.A. is 40 minutes during 'non rush hour' if you're driving a car or taking a taxi (both of which are very expensive). By public transit, the transfer will take closer to 90 minutes, each way, since you'll have to:
1. Transfer to the local rail station by bus or taxi
2. Wait for and then ride the train to Union (rail) Station in the northeast corner of downtown L.A.
3. Transfer to you eventual destination in downtown L.A. To see the Lakers (Basketball) play, for example, you'll need to get off the train at Union Station, descend the stairs into the tunnel under the tracks, follow the tunnel into the station, and then choose one of the following transfer options:
a. Take a taxi to Staples
b. Descend into the red line station and ride the train to the 7th Street/Metro Center Station and then either walk to Staples (10 minutes or so) or transfer to the blue line for the 2 minute ride to Pico Bl station.
BTW, our downtown neighborhood is not in the center of the city of Los Angeles; it's near the eastern edge of it. So, if you plan to visit any other neighborhood in Los Angeles including Hollywood, or the neighboring cities of Beverly Hills, Burbank (where Warner Bros Studios are a popular tourist attraction) or Santa Monica (or other nearby) beaches, you'll have to transfer again from downtown. For example, the express bus from Union Station to Santa Monica takes about an hour.
So, when Dark says that Anaheim is part of the Greater Los Angeles area, that means that it's far away from most neighborhoods in and adjacent to the city of Los Angeles. If you plan to visit the city of L.A. (America's second-largest) and it's neighboring municipalities (like Beverly Hills), you'd be best off staying in the city of L.A. for at least part of your visit.
The city of L.A. will have a much larger selection of concerts. Movie premiers occur in the city of L.A. only.
Why are you staying in Anaheim?
Edited: 12:54 pm, October 10, 2013