OpenTTD moved a step closer to being a Free Software game with alpha releases of OpenGFX, the "[8bpp] Graphics Replacement Project". There's still a few black boxes ("features") where yet-to-be-replaced buildings should be, but it looks fairly good other than that.
Of course, this is just the low-resolution replacement that makes OpenTTD fully free, and is not to be confused with the high-resolution graphics work (see screenshot). The more detailed graphics are [unsurprisingly] less further along.
In the meantime, there is a totally Free Software transport game in Simutrans.
Pak96 Comic [for Simutrans] looks especially gorgeous. Clean, clear, and consistent graphics mean you can focus on gameplay rather than get distracted by artifacts or areas that are difficult to visually parse. The simplistic style has meant they have been able to rapidly create a large number of graphics with minimal deviation in style. There are different climates zones and architectures. Also it's bigger than the oft-tiny-looking standard pak64 graphics (equivalent to OpenTTD's 8bpp graphics) whilst not oversized like the pak128 (equivalent to OpenTTD's 32bpp graphics) can appear. It's a good balance for the standard resolutions today and fun to play - a better experience IMHO than standard OpenTTD or Simutrans. Download it from here.
This release includes a lot of new content, and a lot of bugs have been squashed. It is also -- Macintosh users rejoice -- finally available on all three platforms!
It got extended beta testing and the development seems to be maturing a bit as well. Whilst previous versions have been plagued by long-standing issues, from my observers parapet it would appear they have largely been dealt with. I haven't tried it, but it looks like they have finally fully emerged from the mess that Egoboo once was and it is now a healthy project and a playable game. Congratulations especially to developer Zefz whose determination and dedication have saved the game. Anybody who tries 2.6.8, please post a comment on your experience!
P.S. I'm unable to access the forums currently :-( due to voluntary content restrictions on my Internet connection. However that, in a way, is a good thing. I'm supposed to be programming Fortress, y'see, so now I have less distractions... we'll see how it works out.