I am very sorry for the mistake I have made in the line of Subject.Should be:Handsome Perennials

Last year was my first for this tall perennial; it got maybe 5-6 feet tall. It is rudbeckia 'Autumn Sun'. I bought it from Bluestone Perennials online. The full name is rudbeckia nitida herbstonne.{{gwi:284526}}

Astilboides tabularis
Innula magnifica
Macleaya cordata (spreads aggressively)
Crambe cordifolia
Helianthus ssp. (some may spread aggressively)
Eupatorium ssp.
Rheum palmatum
Rudbeckia laciniata and maxima
Symphytum x uplandicum
lots of ornamental grassses

Other choices for tall "architectural" perennials and/or subshrubs include:

Boltonia 'Snowbank'
Numerous hardy hibiscus (i.e. 'Lord Baltimore' with red flowers)
Veronicastrum virginicum
Caryopteris (various hybrids including 'Worcester Gold'); C. incana is not hardy in zone 5 but make a great tall late season annual with blue flowers)
Filpendula ulmaria
Delphinium sp. and hybrids
Kniphofia (given well-drained soil and protection, some will grow in zone 5)
Lobelia hybrids
Solidago (some are vigorous spreaders)
Verbascum sp. and hybrids

Silphium perfoliatum - huge - about 7' with yellow daisy-like flowers in late summer
Rudbeckia subtomentosa- sweet brown eyed susan - about 4-5'
Thalictrum rochebruneanum - 4-5' - misty lavender flowers, ferny foliage
Sanguisorba tenuifolia 'Tanna' - red pokers, 5-6'
Cimicifuga - various kinds
Aconitum carmichaellii
Persicaria polymorpha
We have about an inch of snow today, so calling these plants to mind is like a quick dose of summer!

A lot of great plants listed for you to choose from. More to add, Veronicastrum and how about the trumpet lilies or Ot lilies such as Black Beauty, Scheherazde, Anastasia,or Silk Road.

Thanks,everyone,for your dedication and effort.
I greatly appreciate all the input.

And yet more--Coreopsis tripteris, Vernonia (ironweed)--both natives.

My standouts in my shady garden were Ligularia 'The Rocket' and Matteuccia struthiopteris (sp? - ostrich fern). Some of the larger hostas have huge leaves and flower spikes up to 4+ feet, and make quite a bold statement in shade/part shade. For a sunny spot, I really enjoy aster 'Bluebird' (it needs staking, but it's amazing in bloom in September/October - it's about 4-4 1/2 feet tall). Also the taller daylilies - 'Autumn Minaret,' 'Golden Chimes,' and 'Hyperion' get 4-5+ feet tall for me, and there are many other tall ones available.

Laurel

And for a hot space how could I have forgotten Russian Sage.

I'm not sure what you mean by "architecural" in this sense, but a proven winner for me is the fall blooming Japanese anemone (Anemone x hybrida) "Honorine Jobert"
Tall (over 3 feet) flower stalks topped by loads of beautiful white flowers that bloom for a good 2 months. Another good one that I don't see mention of too often is Artemesia lactiflora (White Mugwort). It's a late summer bloomer.

Here is a link that might be useful: Honorine Jobert