Greggory: the Roboto fonts are nice, as long as you get the fixed & redesigned 2.0 versions instead of the rather half-baked 1.x versions. I normally install them, along with the Droid font series, on my systems.
Personally, I don't think Workplace Sans is well suited to web page text, although of course it depends on the web page. It's optimized for UI labels, not paragraph text. That's one reason I designed Workplace Gothic (which I pulled from my website a couple of years back while I overhauled it; it's almost ready for a reappearance).
Martin: My ALMSWISS.FON is actually very similar to HELV.FON (by design), only in larger sizes. FWIW, OS/2 doesn't actually require any font besides System Proportional, System VIO, System Monospaced and WarpSans (all of which are built into DSPRES.DLL) in order to run Presentation Manager, although of course some things may look rather ugly without the others. :p (Also, DBCS versions will face some issues, but that's a whole other tanker of fish.)