I am hopeless seed fanatic, when I'm not saving seeds I'm on here reading about it. After doing mostly veggies and perennials, this summer I fell lin lov with a few annuals like zinnias and marigolds. The marigolds I've been using for the past few years are bushy French varieties from saved seeds, but the zinnias were commercial seed California Giant. Zinnias are still going strong even now, so nice to have some blooms, our weather is warm enough but the perennials that I grow have mostly quit blooming. Saving seeds from the double pinks and oranges that we're my favorite, but I guess this doesn't guarantee those colors because they cross pollinate with each other. That is the fun of seed collecting, you never know what youll get. Somewhere I found this list of open pollinate zinnias, which means if you grew them in isolation they would be stable and produce the same offspring. However, I plan to grow several kinds so will end up with mongrel seeds. I don't think this list is complete, there may be other OP varieties.
OP zinnias:
Bright Jewels'
'Canary Bird'
*'Candy Cane'
* 'California Giant'
'Lilac Queen'
'Lilliput'
'Miss Wilmott'
* 'Persian Carpet'
'State Fair Mix'
'Cut n Come Again'
Exquisite