After having learnt the basics on cheapo 9'0 5wt and 8'6 4wt, when I arrived in the US for work (I am european), I decided to try to buy good rods in a logical way to maximize my fishing potential.

I started with a 9'0" 5wt (all purpose trout and small bass fishing), then being in Boston got hooked up on stripers so I bought a 9'0" 9wt, then a 9'0" 7wt to get more fun in the salt and a good stillwaters and big freshwaters.
Then my last one has been a 8'6" 3wt for dries and brookies.

So after 2.5 years of active shopping (to get rods matching reels and extra spools and matching lines)
I have: 3, 5, 7, 9 and I am really pleased.

But I don't know yet if I am going to stop there and spend the next 10 years without buying a single rod... Although they are all lifetime warrantied etc...