Ditto about difficulty being a personal thing. I can grow Phals really well, but I killed a Paph. Dens I've had mixed success. I have Den. Iki that I've had for over a year that hasn't bloomed for me. Yet I have a Den. Purple Prince that I just got that is in bloom now, and there is a new spike growing since I bought it.
I also really like Onc. I have a Onc. Tsiku Marguerite that I've had for a year and it grew well this year and has bloomed for the first time under my care!

So IMO, try a Phal and work your way from there.