My favorites are my Pfaffs 1222E(electric) and 60 treadle. I like the 1222E for its built in walking foot and the 60 for how nicely it sews; its a joy to treadle. I have a variety of machine brands and they all have their specialties.
The Singer Featherweights sew a lovely stitch and are light enough to travel easily, the Singer treadles all sew beautifully and can quilt as well as sew anything I can get under the presser foot.
Recently one of my FW went to the hospital with me to keep me busy piecing log cabin blocks while I had IV antibiotics for 2 days; wasn't sick except for the MRSA on my leg.