I use 2 from Accentsindesign.com , their straight rule and a curved one, both have peg handles, and easy to see lines. I also have a Handiquilter waves ruler ( small one side & long waves on other) , and their Multi tool which has a curved top ( clamshell) a straight edge with 1/4" inset ( sid), a right angle , and a circle for your ruler foot to sit in to guide machine around appliques ( a really handy little ruler...fits in palm of hand nicely. Recently, l got 2 sizes of oval shapes. But the straight ruler and the Handitool are my most used.
For those wondering why the domestic machine's rulers can't be used, the answer is that the thick ones can be...but low shank machines can only fit 3mm thick rulers in behind foot...so those are too shallow for a midarm or longarm, especially if it has a hopping ruler foot.