I've tried a number of amps with my 57's- I won't contradict any of the above advice, it's all reasonable. Just adding my experience to it.
My pair was refurbished by One Thing Audio, so the treble response is somewhat extended, and a "clamp board" was added, which lessens the risk posed by overpowering them. Nevertheless, definitely stay away from the types of SS amps cited above, as those amps could fry.
Some good vintage tube amps aren't optimal, in my experience. Heathkit UAD-1's, highly recommended by some, are too weak. In a well-damped listening space they break up at volume. Getting above 20W or thereabouts really helps. Good transformers- very good transformers- also makes a difference. My Eico HF-81, while great with many speakers, didn't cut it with the 57's. The midrange is great, but the "grip" on the bass is lacking. A Scott 299B also didn't fare well. Neither did an Anthem Integrated One- enough power, great midrange, but poor bass control. Don't even try SET's. A Bedini 25/25 (pure class-A , runs hot) cleaned up the bass and sounded pretty good, but I was tempted to try a Rogue Atlas, as a "shoot-out" featured on a website between many respected contenders had that amp placed second behind a rare boutique German ASR Emitter (sic). I sprang for a used example (not too expensive) and was finally almost satisfied. All previous issues were vanquished- it sounded really good. My next challenge was to try to fill in the lower bass frequencies that the Quads have trouble with. I tried gently supplementing them with a good sub, but it was hard to get it to feel right. So I switched the KT-88 tubes for KT120's, which definitely helped, without fouling up the midrange magic. I also put them on custom stands to raise them about 18" and make them easier to "aim" the sweetspot, which actually matters more than most amp-matching questions. I'm still curious how a Radford or a Futterman might sound, but I'm skeptical the effort to find great examples of these would be worth it.
I can sum up by saying 57's are very amp-dependent, and even those with glowing testimonials may not be best. Experimentation and patience are worth it. Be careful- once you get them dialed in you'll get obsessed with upstream improvements, as you'll really be able to hear the difference they make.