4. I'm on the limit with it though. Hit it well and it gaps properly but sometimes it only goes a few yards further than my 5. It does give me a club to hit low punches with and is one of my most used clubs when I have to manufacture a shot though.
I have a 24 degree 4 iron that I swap out for a 60 degree wedge when conditions dictate.. I did have a 2 iron but found the distance control a bit difficult as it just wouldn't stop running. Use a 3 hybrid now instead that flights a little better for me.
6i, though I have only used it once in the last 3 or more rounds!
Replaced 5i with 27* hybrid a couple of years ago. Simply so much more reliable.
Still happy to hit 2W off the tee (or deck if lie allows) though.
5 Iron on my Callaway XR as the loft is so strong (23°) that is so strong that I didn't see the point in getting the 4 iron at 20.5°.
I don't use it that often, mainly due to the way our course plays, but I do like to use it and there is a great satisfaction from a well hit iron.
This season i took the 4 & 5 irons out of bag because they were only being used for occassional tee shots. Longest is therefore 6, before 4 & 5 hybrids. Only currently carry 12 clubs, and can't say i have missed those irons.
When the ground has been rock hard have thought about putting 4 iron back in for odd tee shot, but haven't done so far.
A Wilson staff 18 degree/2 iron. I think its classed as a utility though so not sure whether it counts for this thread.
I love it though, ball comes out like a bullet with a really low "penetrating" flight which comes in handy on my windy course.
Beyond that I use hybrids up to my 5 iron, although I do sometimes which I'd ordered the 4 iron to my set, but at the time my iron striking wasn't great with the longer ones so thought it would be wasted.