I never got a diaper genie because too many of my friends hated theirs.
I didn't want a changing table, b/c I figured the floor was a safer place for the baby.
We did have a medium sized diaper bag, which I used all the time with DS#1, but got smart after that. I have a small backpack that I used to use as a purse and it's pretty cute. We use it for our diaper bag now and it fits everything we need and DH isn't embarrassed to carry it!
Jogging stroller - I got a double jogging stroller, b/c I was going to be so ambitious and go rollerblading with the kiddos in the stroller. Whatever. I've used it maybe twice and am putting it on Craigslist this week.
Stuffed animals - the kids have their 1 or 2 favorite ones, but the rest are just collecting dust.
Regular double stroller - ok, a neighbor gave us theirs (so luckily we didn't buy one), we used it once in two years and just gave it back last month. I guess this would have been more useful if it would have been a little smaller, but it was HUGE!
Mobile for the crib - We had a great one that played classical music and DH and I loved. Only problem was all of our kids were terrified of the thing! Our youngest liked the music, so we took off the hanging things and just had the music box attached to his crib.
20 onesies in newborn! - My oldest couldn't even wear newborn clothes! He was 8 1/2 lbs and went straight to the 0-3 months clothes.