I like the world cup because it features the only one day games that mean anything (even though the format should be changed to eliminate the horribly stagnant parts of the tournament), and it forces the majority of teams to play abroad (where the true ability of a team can be ascertained).
I know the Aussie and English players would say the Ashes is hands down the pinnacle of cricket but from a young spectators point of view, the Border-Gavaskar trophy is my favourite series. I believe it superior to the Ashes at present because it has featured fiercely contested matches over and extended period of time. In my lifetime (prior to this series) the Ashes have been a joke, and hardly a spectacle from a supporters point of view. If England can take the Ashes this year and back it up with a win in Australia then my interest will be re-kindled. Hopefully it is headed this way and England can live up to the lavish praise the players and their fans are heaping upon them.