Catchy does not automatically equal memorable.
Halo: Combat Evolved was memorable. Skyrim was certainly memorable. Being catchy can contribute to being memorable, but if you want someone to remember your music and think of it right when you mention the game, simply being catchy isn't going to cut it. Whether it's the instrumentation, the tempos, the rhythms, or anything else, something needs to stand out. Catchiness can't carry a piece of music to the Pantheon of gaming music. Something else has to. That's why music from Sonic, Banjo-Kazooie and Assassin's Creed are all so good; it's not just catchy. It's layered. There's a lot of creativity in presenting itself.
Every single genre of music has something worth offering, even pop music. Yeah, I said it. As a fan of progressive rock and progressive metal, I know that complexity can give music a lot of appeal, but that doesn't mean that I automatically hate pop music.
And that's definitely a problem that I see with modern gaming music: they denounce that pop appeal. Should they always use it? Absolutely not, because having a catchy theme would be ridiculous in a game like Ico. But why does everyone hate pop music these days? Is it because it's played on the radio so they're tired of hearing it all the time? Of course there are crappy songs played all the time, but there are also some great ones.
Hate the song, not the genre.
