Mine is the driver. I get to use it almost on all holes because one of my courses near me is very big, and is very popular. So, I whack that thing and never find my ball again! But seriously, what is your favorite club and why?
Mine is the callaway big bertha 454 titanium. I've been using this club for a little while now and I can really catch distance with it. Although I lent it to my brother in law and he couldn't get to grips with it.
My favourite club is any 7 iron. Brand or quality doesn't matter. I find with this particular club that I have 100% control of where my ball is going. Sure I can't hit the ball as far as I could with a driver, but I would still choose the 7 iron over any driver on a shorter course. Of course, if the entire course was massively huge I'd stick with my driver the entire day.
I know it seems like an unusual club to name the favorite but let me explain. Like you may know I am not a great golfer by any means. The only club I can with consistantly is the six iron. I can hit it straight and over a hundred yards every time. That is good enough for me!
I do practice with a lot of other clubs, actually, but the six is the only one I can hit consistantly with. My uncle, who plays a lot, has always told me the best way to get better is to get really good with one or two clubs first. I will eventually try to incorporate other irons and woods.