I know that I have this main site linked in my Dorkroll, but it is worth having an entry for it to bring attention. The original Marvel Super-Heroes RPG (as published back in the day by TSR) is one of my all time favorite RPGs. This site is great, and I have been a fan of it for at least five years now. It reproduces the core rules, and a few of the supplements, for the game in PDF form. If you like super-heroes and/or simple RPG systems and you missed this the first time around...you should go to it now.
Classic Marvel Super-Heroes RPG
"In the early eighties, TSR put out a roleplaying game called, aptly enough, 'Marvel Super Heroes.' The set was less numbers-based, and geared toward first-time players, people unfamiliar with role-playing games.
"The system really took off with the release of the Advanced Set in 1986. New powers and rules were added, the rank system made more flexible, and a number of supplements were released afterward to make for an even richer gaming experience."
This page has a link to a compendium of PDFs of the old Marvel-Phile articles that TSR ran in Dragon Magazine to support the system. There's some good stuff, plus official stats for Howard the Duck (of course I think that would be good stuff too).
Both of these sites are worth checking out. Good games don't die anymore...thanks to PDFs and the internet...they just become something that gets supported by the fan base instead. One day there won't be any more out of print RPGs.