I still haven't found a grass that I like as much as any of the Calamagrostis x. acutiflora like Karl Foerster, Avalanche, Overdam, or Eldorado.

Karl is the plain green but, IMO, the nicest blooms. Eldorado is my second favourite with yellow/green variegated foliage. I wasn't really thrilled with Overdam's performance - maybe I got a dud plant. I moved it last year - we'll see if it does any better. It's white/green variegated but the variegation isn't really very pronounced. It is the shortest of this group. And I only got Avalanche last year so the jury's still out but it has received rave reviews on this forum and others.

Reasons I like this grass: cool season so it starts growing early leaving only a few weeks in the spring that look bare. The inflorescense goes thru a variety of bloom stages - thin & purple tinged, puffy, thin again, tan as they mature. Foliage holds up well thru winter. Rock solid hardy in my zone - have never lost one. The grasses are tall but not huge around. Karl will get to 5' with blooms, but the others are shorter in my yard - right around 4'. Best of all, the clump increases in size over the years but no runners and no seedlings.

Not a foliage plant but I think worth mentioning - Monkshood grows in my yard in full sun and part shade. With blooms it is also around 4' tall and always holds up to our prairie winds. My mom has a row of these backing her perennial garden, dividing the flowers from the vegetable patch and they make a really nice background plant. I actually like Monkshood somewhat more than Delphiniums - the bloom time is longer, the foliage looks good throughout most of the season, and they're sturdier. One of my favourites.