Welcome to the forum!
I agree the 06 LBZ is the best.
However, If your looking for a truck just to work and dont want to mod alot then a LLY 04-06 LLY would be a great choice as well. Some of them do tend to everheat but of course not all. Those are one hell of a truck and you can pick them up at a resonable price as well. the 01-03 or so LB7 (early duramax) are known for injector problems. Gm upped the warranty to 200K miles from the 100k miles stock and 7year. A few of my friends have LLY's and are extreamly happy with there power and durability.
