My immediate answer is Muller, but the more I reflect, the closer I think it is. How the heck did Linden end up with 30 more points in three fewer playoff games? My god...
Yeah, this is one of those things that on paper looks like, 'Oh, Muller had the best offensive seasons + a Cup, he takes this' but when you dive deeper ... I'd certainly take Linden (although I might be biased).
1. Linden to me was a better defensive player than Muller, who as mentioned earlier in the thread was kind of one of those guys who had good defensive play attributed to him because he was a gritty square-jawed guy from Kingston rather than that he was actually really good defensively. Linden was also a bigger, more physical player.
2. Linden was an absolute monster in the playoffs. He was a Claude Lemieux who just never got to play for a consistently elite team. Best Canuck every year, upped his physical game in a huge way, one of those players who legitimately turned into a postseason superstar. Even in the 2007 playoffs when he was 37 and nearly finished he stepped up the team's best forward and led the Canucks in playoff scoring.
3. Usage. I've mentioned this before, but Linden really only had one stretch as a 'first liner' in the prime his career, when he scored 50 points in the first 40 games of the 91-92 season at age 21. Then Pavel Bure exploded in the 2nd half of that season, and for the rest of his prime until his 96-97 knee injury he was pretty consistently on a high-leverage 2nd line while the Bure and/or Mogilny line got the top creamy offensive minutes. Muller by contrast was the undisputed 20+ minute #1 C for NJ/Montreal for several years. I think this explains away quite a bit of the production disparity.
4. Better career finish. Both guys had a major crash from impact players to depth players around age 27-28, but Linden was still a substantially superior two-way player and outscored Muller by basically a 2:1 ratio in their age 31-32 seasons as an example. Muller fell off much harder and was basically a fungible 4th line player for most of his 30s while Linden averaged 40-45 points/82 from age 30-35. And had some big highs like that 2007 playoffs.