Depends on how you're flying. Or which airline you are going to fly on. If you don't care, but want to fly on an airline, then ONT requires the least driving to get to from my work or home.
If you're flying a private airplane, I'd recommend landing at Chino or Cable. My work is just down the street from Chino.
If you want to fly the cheapest, LAX is the best bet usually. You can take a train from LAX to Rancho Cucamonga, Pomona, or Upland for $9 for the metrolink after taking the $5 (I think) LA Metro green line connecting to the red line to Union Station, or just take the flyaway bus there for $6. Another option than taking the metrolink is taking the Silver Streak bus from the Pomona transportation center to LAX. It's $3, I think.
I posted a big thing on how to get to the IE here.
If you're flying a private airplane, I'd recommend landing at Chino or Cable. My work is just down the street from Chino.
If you want to fly the cheapest, LAX is the best bet usually. You can take a train from LAX to Rancho Cucamonga, Pomona, or Upland for $9 for the metrolink after taking the $5 (I think) LA Metro green line connecting to the red line to Union Station, or just take the flyaway bus there for $6. Another option than taking the metrolink is taking the Silver Streak bus from the Pomona transportation center to LAX. It's $3, I think.
I posted a big thing on how to get to the IE here.