I'm using a SitOnIt Amplify task chair at home.
Every once in a while, my company makes used office task chairs available for purchase for $40. This past sale, they had Herman Miller Aeron, Steelcase Leap, and SitOnIt Amplify. I chose the SitOnIt over the other two for home use.
Aeron chairs are pant shredders. If you keep a wallet in your back pocket, the mesh-like ventilated material will wear pants at the edges of the wallet, especially if it's a softer khaki or dress pant. It became a running joke about everybody walking around the office with wear marks on the seat of their pants because of our ultra-lux $1,000+ office chairs. The company eventually bought seat covers from Herman Miller. Even the seat covers eventually wear out though. None of the Aeron chairs for sale had the covers anymore (probably stolen/kept for the chairs still in the office).
Steelcase Leap is the other "primary" task chairs in our office. I prefer them to the Aeron and it's what I sit on when I'm in the office. The ranges of ergo adjustments is far better than the Aeron. It's a really bulky chair though and better suited to a more open office space rather than a smaller home office. Like the Aeron, Leap are $1,000+ at retail.
My company used the SitOnIt chair in conference rooms. They kind of split the design between the Aeron and Leap. The back is a mesh-like material, but the seat is a traditional fabric. Tons of ergo adjustments (not as many as the Leap, but more than the Aeron) and it's svelte enough for a home office. Their size is why they were used in conference rooms, which are a little tighter than the open office.
Great thing about the SitOnIt chairs: You can find them at retail for less than $300. It's a little more than your typical office chair at Staples but it the quality and comfort is so much higher.