Sedums have always done well for me in heavy soil. Try Sedum "Mr. Goodbud".

Rudbeckia "Goldilocks" does well and is a favorite of mine.
Hollyhocks do well.
Penstemon "Husker's Red", "Dark Towers" and "Mystica" all do well.

Salvias do well.

You can improve the soil and grow many more plants. I know I've been working on mine and it really has made a difference in overwintering the plants, especially Echinaceas.

Rudbeckia 'Goldsturm', hostas, daffodils do very well in heavy soil.
Keep on adding compost, leaf mold, manure. Earth worms will do the rest for you.

Amsonias do best in heavy soil. Also, look at High Country Garden offerings. Most of the area they specialize in are heavy clays; though many of the plants they offer won't overwinter well in the wet east, many will.

I have clay soil but it's on the loamy side. It's not backbreaking to dig.

Yes, Rudbeckias do well. 'Goldstrum' took over a full sun bed I had at one time and ran over all it's nice neighbors, so I took it all out. I do still grow Rudbeckia 'Indian Summer' which I find much more well behaved. It gently reseeds but they clump rather then spread.

Salvias do just okay for me and I have to grow them in a raised bed. That and lavenders would rather have better drainage, especially in the winter. Creeping Thymes also resent the wet winters and also peter out unless I grow them along the edges of my raised beds.

Off the top of my head...Echinaceas, Perovskias, Pennisetum 'Hamelin', Peonies, Delphiniums, Aquilegias, Hostas, Hellebores, Ferns, lots of Shade plants and Ephemerals, should all do well.

There are lots more too. Any soil, clay or otherwise will be better if you continue to amend it with your own compost, and leaf mulch.

In my clay I grow most of what you do. Lavender, Heuchera, Hosta, Mums, Salvia all come to mind that also have lots of foliage.
Cher

Hmm, about the only thing I've had trouble with is dianthus. Aside from that, it's a very long list. Things that haven't been mentioned so far are phlox, siberian iris, epimediums, pulmonaria and hardy geraniums.

It sounds like we should back up a bit. What plants have not worked for you? How has the soil been prepared? How much sun do they get?

I have lost multiple Dianthus, Coreopsis, Echinacea, Corydalis in my clay soil even though it has been amended for years.

Perovskia, bearded Iris, Brunnera, Roses, Clematis integrifolia group, Lilies, Lavender, Rosemary, ferns, Sedums both ground cover and upright like 'Autumn Joy', daylilies, Peonies, hardy Geraniums, Hosta, Huechera, heathers and heaths, some columbines, Dicentra, Helebores, daffodils, crocus, hyacinths all have done very well over the years. Ornamental grasses too. The only one that died over and over was the 'Red Baron' blood grass. I have at least twenty others of all sizes, Hakone, Fescue, Miscanthus, Pennisetum, etc.

Lily of the valley, Muscari and sweet woodruff have done too well.

The trick to keeping dianthus in heavy clay soils is a pea gravel skirt under the plant, they dislike direct contact with the soil. You must never keep the crown wet. Go out there after a rain, and shake off the water from the leaves. lol They do really well here in my clay soil (also on the alkaline side), with just a little extra attention.

Definitely trying to focus on prolic bloomers with a nice mound of foilage throughout the year.

I plan to mass 4 perrenial types in the front yard that will have full sun and bloom at different times but will be in seperate beds.

Any ideas with white, pink or purple blooms?

Success that I'd recommend as prolific bloomer with attractive mound of foilage throughout the year:

Daylily (most any)
Purplicious Speedwell
Coreposis Zagreb
Blue Clips Campanula
Snowcap Shasta Daisy

Failures:
4 of 6 Plum Pudding Coral Bells
2 of 4 Kim's Knee High Coneflower
2 of 2 Mammoth Mums
1 of 3 Jolly Bee Geranium
1 of 3 Rozanne Geranium
1 of 3 Shasta Daisy

Maybe thats not that bad...just seems like alot based on the number of plants I purchased.

I recented bought several perrenials just to "try" so I bought little pots.

They include:

Farmington Aster
Woods Pink Aster
Sheffield Mum
Blue Hill Salvia

Trollius, Thalictrum, Iris sibirica, Helenium, Phlox, Lilium martagon.

Heliopsis, helenium, Asclepias incarnata, lobelia, hemerocallis, hosta, phlox, lonicera, ceratostigma, eupotorium, and the list goes on and on...

Karen

Not sure how hardy they are for your zone, but if you have some shade and moisture, Astrantias do really well in heavy soil...as long as they get some shade and the soil doesn't dry out.

astilbe do great in my heavy soil, full sun bed. Also Filipendula 'Kahome', Campanula poscharskyana Blue Waterfall

If the soil retains water well, you can get away with typical shade plants in a sunny area. I have Hosta On Stage that gets HUGE and gorgeous in that environment and never a sign of dryness. I also have a blue one that doesn't stay too blue, but still does really well. Its nice to have large-foliaged plants mixing in with the regular stuff.