There is quite a bit of subjectivity involved in color perception. That's one problem in answering your question. Another problem is lack of any information about your location - what can be seen driving around near Seattle would be very different than what could be seen near Boston, for example. At least in the East, Nova Zembla is the most widely planted red and pretty much the only red available at the big box stores. Nova Zembla contains to my eye quite a bit of blue/purple and is not really a true, saturated red at all. It does have great hardiness and grows huge with time. There are, imho, much better reds to be had, but until your location is made clear, not much point in listing them.

Oops! sorry about that, akamainegrower, and thank you for your response. I live in Ma.. zone 5 and sometimes I've seen it as zone 6. I've often wondered if I should just knock on a door and ask the owners the name of their planting. Unfortunately, if they're anything like me, they only know half of their plants having forgotten what the others originally were. I will have to try to find Nova Zembla and see how that compares. At least I would have a starting point to know whether I need to go redder. When I see the rhody I've admired, I think red. Upon reflection.... it's not just red but with a tinge of blue. I think it's quite stunning.

Nova Zembla definitely has a tinge of blue. For many this makes it less desireable, but taste is entirely individual. For what it's worth, my favorite larger growing reds are Vulcan, Henry's Red and, especially, Keith Brown. None of these are as widely available as Nova Zembla, but the last two are hybrids from Weston Nursery in MA so may be worth looking for there. None of these three are noted for the blue tinge you're seeking, though.

I will check them out. Weston Nursery is not too far from me so researching them now won't be a problem since you've given me some guidance. Thank you.