I read Meat first, and I stand by my belief that doing so is in some sense optimal; a lot of what makes Candy tick feels like payoff for threads established in Meat. (Obama Ex Machina in particular follows up a gag from Meat that I don't remember having any presence in Candy in otherwise, though I could be misremembering.)

As for my route preference, while denpa is cool and all, Meat's high-concept action is so completely and utterly My Shit that I ultimately end up vibing with it more than I do with base Homestuck. I would read an entire adventure hinging exclusively on the narration-battle mechanics. (inb4 "but Ruki, that already exists, that's just Umineko!") Candy is, of course, also cool and I am always a fan of extreme mental breakdowns, but my favorite single page of Homestuck in general is Meat 32.