Well, first of all, I rarely ever get to a place where I have access to Wi-Fi, so I can't really comment on the library of either too much. Based on what I know, have seen, and have bought, however, I will say this:
Virtual Console: If I really liked most of those games, I'dve bought them the first time around. However, that isn't always the case, and I've thusly purchased Mario Kart 64 (didn't age as well as I'd thought), Super Metroid (just can't get into it all that much... hey, I was weaned on the Prime trilogy), SB2J (mostly for nostalgic, non-Nintendo value. I don't think I've ever played it--for obvious reasons), and Kirby 64 (short, but tougher than the average Kirby game!) since obtaining my Wii. Great source of old-school titles... but it's so odd that there's TG-16 games...
WiiWare: Never really browsed the catalog, but it seems to me that most of the games are stuff that's on PC or UgoPlayer. Question: With all the insubstantial games released on store shelves for the Wii, how do the devs that make that stuff decide whether to go the downloadable route? I mean, there's games on WiiWare that could've been released in stores--and vice-versa.
Eh... I'm not buying a whole lot of it, but VC games for me.