5 is more direct but boring. Once on 5, Anaheim is straight. I am assuming you are going to DL? If so it is right off 5.
101 has nicer sceneries and you get to cross Santa Barbara, Ventura etc... but you will have to switch highway to get to 5. I recall you would have to go onto 134 past Disney Corporate offices then right onto 5 South to get to DL.
Taz
CA_Stitch