Colder winters is better for tulips returning, so that's one time to be glad for a colder zone. I've had good luck with species tulips returning well. This one, 'Honky Tonk' from Brent and Becky's has been the best- 7 years and still going strong.
I love the straight species of T. linifolia. I've had those hang on for 4 -5 years, but I think rodents got into them. Got some more going last year, time will tell if they'll be more permanent.
This early single, 'Flair', is described as a good perennial in Brent and Becky's catalog- they said it has returned for years in their garden. I planted several for the first time last fall.
Darwin hybrid tulips, especially the older varieties like Apeldoorn, Golden Apeldoorn, and Parade, return pretty reliably too.
