I'm sure this MUST have been mentioned here already, but just in case...
Gerry Anderson’s UFO
Here’s a glimpse of a comic that never happened, a comic based on Gerry Anderson’s UFO, a 1970 live-action British Sci-Fi series from the same producers as Space: 1999 and Thunderbirds. A comics publisher had secured the rights to a comic book adaptation, and a 7-issue mini-series was mapped out. Issue #0 would have taken place immediately after the TV series, and would have essentially acted as a series finale. Issues #1-6 of the series would have picked up more than a decade later, acting as an epic sequel to the TV show.
The pencils, inks, colors and lettering were completed for the #0 issue, and pencils to #1 were underway when the plug was pulled at the publisher end due to lack of funds – another project that had been expected to fund this one hadn’t been the success that had been hoped for, and the money to produce and publish the mini-series wasn’t there. Valiant efforts to save the project were made, but the whole thing just folded. I’m happy to say I was paid for the work I completed, but I really wanted to see this project reach an audience.
The inks on the book were by Joseph Rubenstein whose work I’d known from everything from the Official Handbook of the Marvel Universe to some of John Byrne’s issues of Captain America. The colors were by colorist Matt Webb.
Here’s a taste of the comic that might have been...
(Taken from the website of artist Christopher Jones. Although he hasn't captured the likenesses in all cases, generally the artwork is of a VERY HIGH standard indeed and some of the pages are extremely dramatic and original in design and execution. A shame it never took off, so to speak.)