It all depends on what you like to sew and how you like to get it done. Particular singers I love: the 201, 66, 99, 15 and anything earlier. Sweetest straight stitchers from singer. But for carrying around the 221/222 or 301. Love the Japanese 15 and 99 clones for the same reason, they do one thing and extremely well. Also enjoy the later 'dashboard' Japanese machines, some are amazingly complex and yet still sew amazing stitches, either by an internal cam stack or via individual cams. Same goes for most of the Singers until the 'touch n sew' machines after the introduction of non-metal gears.... all metal is all good. Consensus is not going to happen. We all have different needs and interests and some machines fit better than others .... and I'll take anything on a treadle, even if I do have to stand on my head and spin circles to make a currently manufactured needle work in a machine that takes an obsolete one... or a weird bobbin or bobbin case, and I love a shuttle on a treadle and the mellow 'swoosh swoosh' it makes.... And of course the German, Swiss, Italian and Swedish made machines of the last century are some amazing engineering marvels.
Okay, I'm easy, I like most of them made before about 1960... but even new 'modern' computerized machines have their place but they don't make my heart go pitter-patter like the stately ladies of days gone by do...