City Works in Market Square is a massive pub with a huge draft list, and it's perfectly situated in PPG Place for after work happy hours and watching sports games on one of their 15 TVs.
We visited on a recent week night just after happy hour had ended, and it was bustling with large groups of professionals enjoying the deals ($4 rotating drafts and select $4 appetizers). While we were sad about missing out on the specials, we dove in to our meal all the same.