Very impressed with the Poly Head tut and Dragon Project. I've gained a lot from watching the techniques and tricks used and found them clear and entertaining. A lot of help for a newb/hobbyist!
I have a tutorial suggestion though given that most of the modelling tutorials have been character-centric. I'd love to see something that's less open to interpretation such as a car or a plane while still having a some degree of complexity. A car or a fighter plane for example?
My first instint is to use nurbs to lay something like this out but I run into little issues at parts where more details is needed and I'd love to see someone who knows what they are doing demonstrate
"Blueprints" of an Enzo attached as a suggestion