really hard question, as I love all Illusiones!
The 68 is one of the best petite coronas on the planet, no doubt.
The Cuchillos Cubanos is one of the best $3 cigars on the planet, no doubt.
The 88 was my first Illusione, and is still one of my favorites. I also love the super-charged MJ12. But as I said, I like all the "Original Document" Illusiones that I've had).
The Eperany line is a truly amazing cigar ... I've only had two, sadly, but both were awesome. They had the pure, rich tobacoo flavor of the original Illusione, but with more complexity of flavors--a "nougaty" flavor, to quote the Maduro Kid--and slightly less strength, imvho.
There are still quite a few I have not had (Holy Lance first among them), but I look forward to trying them all, as these are in my Top 10 cigars!