Have been using, so far, Ronson Multi-Fill. I don't recommend it, although I haven't had any clogs yet.
Learned that the owner of a good B&M hereabouts has advised his jet-flame lighter carrying regulars to use triply-filtered butane. Sure enough, after a couple of weeks, a clogged lighter becomes unclogged, merely by changing fuel.
I saw some 5x-filtered butane with a Buy Now price of about $2/can - and these were big 7oz or 10oz cans as I recall.
Have switched from (thanks in large part to TSA vigilance being a bit more stout in Oakland than at LAX) Colibris, which I never liked, to Ronson Jet-Fire lighters and love 'em. However, once I'm done with the aforementioned Ronson fuel, it's going to be 3x- or 5x-filtered butane for me.
Haven't put anything but Ronsonol into the Zippo-lookalikes (Windii) - same yellow-blue flame, same wick/flint/fluid maintenance merriment - nothing new to report there. I use them as carry-on backups in case I forget to not travel with the torch lighters.