The Lyr, Uber Bifrost and HD-650's are my current setup. Here are the tubes I have tried:
JJ E88CC - Came with the my Lyr - Okay, but I would pass
GE 6BZ7A - Minimal improvement over the JJ's but nothing special, I would pass
Toshiba 6DJ8 - A noticeable improvement in sound, but nothing special, I would pass
Philips JAN 6922 - A seriously good sounding tube. These are good for what they cost, but still a long ways to holy grail tubes
CBS 6DJ8 Made in Germany - Was told these were good alternatives to Telefunkens at a fraction of the price. Didn't really care for them.
Amperex 6DJ8/ECC88 Orange Globes - Great Britain Small O-Getter - Very nice, very lively tubes. Was told these were relabeled Mullards. One of the best I have heard.
Amperex 6922 JAN White Label Large O-Getter - Very similar to the Orange Globes above, but larger soundstage and clarity extension. Missing some extension on the low end. Great sounding tubes, but for what they cost, I think there are better
Telefunken ECC88 - These tubes are in my Lyr right now. They are my favorite of the ones I have tried so far. I would highly recommend to anyone looking for great bass and and impressive soundstage and great dynamics.
I'm still rolling... but I loved the Telefunkens so much, I bought a spare set!