As founders of three startups, we have tried many chairs over the years with employees.

The single chair that has performed the best ergonomically, economically, and wear-and-tear-wise is the Herman Miller Mirra.

The warranty described in Joyce's tweet is a bonus.

We have found the Mirra to be more durable than Herman Miller's other popular model, the Aeron.

Also, the larger employees among us prefer Mirra's with the Extra Support option.

By the way, even Lifehacker says a great chair is one of the most important things you can buy.

With that in mind, there are two other chairs I'm a fan of:

1. HumanScale Freedom Task Chair with Headrest -- it's customizable and also favored by Bill Maher and the FBI. The one I bought is the HumanScale Freedom Highback Std Fabric with Vinyl Arms 992 Graphite Base Auto Headrest Dual Pivot Backrest which I got from OfficeDesigns.

2. SwingChair -- an ergonomic office chair specifically designed for people with bad backs.

Interestingly, Four Hour Work Week tried all four models I just mentioned (Mirra, Aeron, SwingChair, and HumanScale Freedom Task Chair with Headrest), and decided to go with Isokinetics Balance Ball Chair and a Herman Miller Chair.

Most important chair habits for avoiding pain:

• Lumbar support is key.

• Seat height should keep your knees and hips the same distance from the floor with your feet flat.

• Use a foam roller three times a day.

• Get up and walk around at least once an hour.

See also:

• Quora: What is the best office chair?

• Lifehacker: How to Ergonomically Optimize Your Workspace

Absolutely love all of the herman miller chairs, though I need a size C. I wore my last 3 out, but they were used on Ebay when I got them anyways.

I must sit in this Mirra to compare it to the Aeron!

Remember that standing is healthier for you than sitting.

Stand whenever you can.