It is true that some burners are crappy with say 90% of the media. They work fine with the other 10%.
Then there is media that is crappy with 90% of the burner. But works ok with the other 10%.
So there is no ONE SINGLE brand of burner or brand of media that can be recommended. If you have a crappy burner (i.e. one that is very old or a laptop one), you are going to have to go through lots of media to find the one that works for you.
If you have a very good burner, you could still come accross "crappy" media that won't work rigth for you (will be hard to read by most readers).
So we can only give you general advice. In general, Pioneer (some models) and Samsung (some models) are good double-layer burners. And in general, Verbatim is the best double-layer brand, more specifically their media with the label DVD+R DL 2.4x-6x on the box and the made in singapore label.
But the poster above is right. The Verbatims DL made in india (as oppossed to the ones made in Singapore and elsewhere) are just as crappy as other DL brands. And their DVD+R DL 8x labeled media is different. Also good, but not as good as the 2.4x-6x media.
So another example that we can just not give you a general recomendation. You have to keep trying to see what works for you. And if you have a crappy recorder, giving that you are gonna have problems with 4 or 5 different brands/speed combinations before you get a good burn that your Wii can recognize, at $3 for each blank disc, it may be chearper just to buy a new burner for $40.
That's also not accounting for the fact that some Wii's are going to read some discs better than other Wii's. If you have a Wii factory calibrated with the laser "a bit weak", it would be possible that a burnt disc that works fine in a friends Wii doesn't work in yours (where you would require an even better burn for your Wii to "see" the disc properly). A repair house tested Wii's lasers informaly and found that up to 50% were tuned too low for proper Dual Layer RECORDABLE media (this is not the same as PRESSED ORIGINAL media, which is always "much better")
Again, you can read the article in ign.com or tgdaily.com about some Wii's freezing and having disc-reading problems EVEN on the ORIGINAL high-quaility disc and Nintendo claiming that it was because dust and smoke made the lenses dirty and not properly able to read the dual layer game
IGN: Nintendo to Clean Japanese Wiis Over Smash Bros. Errors
So, again, before you suspect problems with anything else and start blaming the modchips or the firmware etc, you MUST try at least two brands of disk, at two different speeds, on two different burners and with two different recording softwares (