I’m a big fan of Gotham and Sentinel. Both fonts work really well in isolation or when paired. I find the pairing works especially well when Gotham leads (headers, sub-heads) and Sentinel supports (paragraphs, list items).
Gotham & Sentinel Pairing
Here’s an example of the pairing in an agency theme I’m currently designing:
By the way, notice how KILLER Sentinel looks when italicized?
This awesome font combo costs about $99/year though. I can’t possibly ask customers to spend that much for a theme purchase. And so began my search for free alternatives.
Droid Sans & Droid Serif
Gotham & Sentinel VS Droid Sans & Droid Serif
Here’s a side-by-side comparison of the two pairs:
I didn’t touch any CSS for this side-by-side. This makes the differences between the two fonts a lot more apparent.
I do favor the Gotham and Sentinel pairing slightly more. However, the Droid Serif and Sans combo comes close and frankly, it delivers: It’s legible, consistent and free. I’m confident that CSS tweaks in the letter-spacing, font-sizes and line-heights will get the Droid combo to where it needs to be for the overall look-and-feel.