What do you guys consider "business casual"?

The answer to this will change depending on where you work. I work in Houston where business casual is is typically more casual than elsewhere, so incorporating the occasional fitted polo into the summer business casual look has been fine although I personally reserve those days for Friday.

Business casual can mean a number of different styles but the most straightforward answer would be to wear a pressed pair of khakis and a button up shirt.

However, depending on the environment and the office structure it can be permitted to wear polo shirts as well as golf wicking shirts.

If you wear a coat, skip the tie. If you wear a tie, skip the coat. That's business casual. It's a dress code made for office workers (who traditionally wear a suit) to wear cooler clothes without sacrificing appearance. It's not an opportunity to let people wear casual clothes, although the definition seems to have gotten very flexible.

Slacks, button down shirt, no tie. Polos are kind of a jump ball. I tend to see what others are wearing first before going there. Being the only person in a polo at the office can draw some glances.

No sneaks, no t-shirts, no jeans.

I tend to model on what my boss is wearing, let them set the tone.