We go to DL almost every year - though last year was probably our last time for a long time. Our daughters are older, and they enjoy WDW so much more.
We've flown into LAX, SNA, and LGB (Long Beach). LAX is too big, and the traffic to get from LAX to DL is horrid, unless you land later in the evening. SNA is OK and closer - don't mind that one. Out of all 3 airports, we prefer LGB the most. It is a smaller airport that is 20 min. from DL. You literally get off the airplane, walk a few steps to the baggage carousel, and the car rental is steps away. I also find it costs me less to fly into LGB from the west coast.
We always rent a car, so can't really tell you about the cab or shuttle. Don't really recommend the cab though. That would cost you a small fortune, esp. if you get stuck in L.A. traffic. Have you looked into renting a car? If you do decide on a shuttle, pick a smaller shuttle van (like a Mears shuttle van) so there are less passenger drop-offs along the way.
We always buy the 3-day hopper. That seems to be just enough for us to do all the rides and shows we want.
Other tips...
1. When you go to DL, don't forget to get your coffee at the Main Street Market (near the fruit stand) and then keep your receipt. You get free refills the rest of the day - that is, if you can stomach the Nescafe stuff.
2. Make ADRs for Cafe Orleans. Their gumbo soup, pommes frites, montecristo sandwich, and beignets are really yummy. Their food comes out of the same kitchen as the Blue Bayou, which is really nice in terms of ambiance but really pricey. Af Cafe Orleans, you pay slightly less for some of the same food items.
3. If you do end up renting a car, hit the Target store on S. Chapman and S. Harbor Blvd. for bottled water and other things you may have forgotten or need. Also next store to the Target store is a Dollar Store that sells Disney-themed souvenirs for $1.
4. Go to Mimi's Cafe for breakfast/lunch/dinner. It's across the street from the Disney front gates on S. Harbor Blvd. Huge menu, good food, and good prices. They have a website if you want to check out the menu.
5. Go to the Anaheim Garden Plaza for shopping/eating. It's on Katella, near S. Harbor Blvd. There's a Cheesecake Factory, Bubba Gump's, CPK, PF Chang's.
Have a great time at DL and enjoy GCV!