I will soon be starting the consulting gig, with DEN as my homebase.
I was wondering what people normally do: do you drive your own car, use taxi, limo,... to get to the airport.

Personally, I enjoyed taking public transportation when I lived there. I still use it when I go back to visit. RTD's Skyride service (see the link on the left-hand side of the page) is pretty convenient ... if you're close to one of the lines or don't mind leaving your car at one of the Park 'n' Ride lots.

I drive and park or have my wife bring me. Taxis are very expensive.

When I lived there, I always drove in and parked at the Pike's Peak long-term lot. Relatively cheap. Only problem would be the occasional hailstorm, or roaming tumbleweeds.

I drive and usually park at USA Parking (usually covered), though for a short trip during which thunderstorms/hail/etc. do not appear likely, I might park at Pike's Peak. However, with a AAA discount, USA (uncovered) is just a little higher, and they pick up and drop you at your car (and help with bags if needed). Covered parking (think carport) is a bit lower than the airport's parking garage.

I have taken the Skyride to the airport when I was meeting someone who was renting up a car. It wasn't bad, but the lot location, bus schedule, and leaving a car parked in an open lot overnight have discouraged me from using it otherwise. I could see it working for someone who had easy options of getting to and from one of the stops.

First choice is to get my wife to take me if the times are right. Second would be the parking lot formerly known as PCA on 56th a mile east of Tower. When you fill up a 30-day punch card you get a certificate for 10 days worth of free parking. Sometimes I'll take the Skyride if I'm leaving from downtown, but the schedule is once an hour through most of the day and that usually leaves you too close or at the airport for too long.