I've always had a mixed opinion on Nintendo, which I think is pretty reasonable, since they make so many different games. I'm not one to think they peaked years ago or when I was a kid, or they're at their best right now; some franchises were better than, some are better now. Comparing Wii to GC, I think Galaxy 1/2 are MUCH better games than Sunshine, which honestly I think is a bit crap. TP is kinda a wash, but I definitely think Skyward Sword has WW beat, with much better dungeons, the best 3D combat in the series, my favorite collection of NPCs since MM, and an dense underworld that's a lot more fun to explore than sailing ever was. I'm in the Anihawk/Mark Pacini camp of Metroid Prime 3 being more fun to play than MP1/2. Donkey Kong Country came back and it was one of the best 2D platformers of all-time. Punch-Out came back and it was awesome, too. Somehow Treasure convinced Nintendo to fund a Sin and Punishment sequel and that was one of the best action games of the generation.
Of course, there were the disappointments. I don't think Brawl holds a candle to Melee for a variety of reasons. Super Paper Mario was pretty wack after Thousand Year Door. And no Star Fox, Wave Race, F-Zero the entire generation still kills my soul.
GBA vs NDS is a bit more in favor of GBA(Minish Cap >>>>> the DS Zeldas, Advance Wars 1/2 > Dual Strike/Grimdark, Metroid Zero Mission/Fusion >>> Hunters, etc), but I did feel Canvas Curve is the best Kirby game, and Bowser's Inside Story the best in that respective franchise, so its really not all black and white.
Its just as its always been nowadays. Pikmin 3 was the most refined entry in that franchise's history. Dream Team was waaaaaaay too long and pretty disappointing after Bowser's Inside Story. Sticker Star was just trash. Wonderful 101 was awesome. NSMBU bored me to tears. SMB3DW looks great. LttP2 could be very well be my new favorite 2D Zelda. I've lost all interest in Pokemon a decade ago, and nothing I've seen is asking me to go back. I'm very much looking forward to DKCTF and Bayonetta 2 and hope Smash Bros has found a happy balance between Melee and Brawl. So yeah, its business as usual over here.
The main thing I've learned after living through the N64 as my sole console; NEVER has Nintendo as your sole console. Sooooo much variety out there you'd miss if you depend on them as your only game-maker(and the occasional third party exclusive that slips through the cracks), playing shovelware during drought months in-between releases while others are on The Last of Us and Guacamelee and shit. Plus, it kinda puts a lot of pressure on Nintendo to deliver all the time, and that's bound to lead to disappointment. They're good for at least 3 great games that'll end up in your top 10 at the end of the year, but one can not live off their franchises alone. I've owned every major console during both of the previous generations, and i'll probably do the same here. Not having any huge expectations for them to constantly deliver makes it much easier to accept when they don't, and much sweeter when they actually do.