Oh goodness, did I ever! Not "flats" full though (geeeeeze!)
One year I started watermelon indoors and got one melon per plant (only two plants lived!) ha ha!
One year I started delphiniums and they were doing ok until I read something about them being difficult to grow, so I worried them to death and they died.
Same year as delphiniums I started foxglove and they lived!!! I nurtured them all summer and they made it through the winter. I was so anxious to see them bloom (biannual) and one day my sister (who NEVER did yard work EVER) PULLED THEM UP WHEN SHE WAS WEEDING! I nearly cried (and nearly killed her). I was 20 then and she was 18 or 19 (we are only 18 months apart) and it was then that I started my interest in gardening. What a miracle it was to watch those lifeless seeds sprout into green little delicate seedlings and then grow into mature, flowering plants. Also started me on my philosophical path, I suspect...
Since then I've started moonflower, morning glory, zinnias, more foxglove, and probably lots of other plants, indoors. I had lots of luck sowing the following directly into the ground here: sunflowers (everything from bright yellow to chocolate brown), nastirtiums, morning glory, and zinnias. The $#@! morning glories have turned into weeds and they grow all over after re-seeding themselves. I only planted nastirtiums in the fall of 1999 and yesterday I was out weeding and found one growing right next to my jasmine!!! Silly thing!
Good luck, Vanessa!!! Heck, go out and get some stuff to start them indoors anyway. It's been a long winter!