I have always thought the widows were about as tough a bow as you could get overall.The longbows they build are incedibly tough as well as the recurves.
I agree with Chad.The deep cored longbows are super tough bows and I think the straight limbed or mild R and D versions may have an edge in the keep on ticking department in the case of abuse.
I think the Big Jim Buffalo Bow is a mighty strong longbow as well.He has a touch limb that could withstand some torture testing IMO.
I like the Great Northern bows as well for a resilient quality.Thier are plenty others I am sure.My Fredericks could withstand anything I could dish out year after year.Dry fires etc.You name it.They never failed me in the least.