My first 2 exes were much worse, but my last ex broke up with me because she said she didn't see me going anywhere in life and that she needed someone with a stable future (job/home/etc). It was really a wtf moment because I was a freshman in college and she was a junior. The biggest slap in the face was that I had worked a bit on weekends to plan a nice date and got her a $100 ring for our one year anniversary. We ended the night at like 11pm and I get a long email the next day at like 7 am explaining why she is breaking up with me and that she has to move on to better things.
Edit: I actually completely forgot, that wasn't my last ex that was the one right before. My last ex we were really good friends for like a year before I asked her out. She finally said yes, unfortunately it was like 2 weeks before finals. We went out a bit when we could spare the time during the finals and summer break hit. We talked online almost every day for like 3 hours. Finally the next year rolls around, I get back into town and she's like omg I missed you let's meet up. I went to the meeting place like an hour rolls by, she's not there. I send her a text, shes like omg so sorry I met a friend on the way, I'll be there shortly. Another hour rolls by and I send another text and she responds that she had to run a couple of errands and got stuck on traffic but she's on her way. This goes on for quite a while. Finally after hours of me sitting in a mall like an idiot. She sends a text that she has to catch a train because shes going out of town for the weekend and she'll swing by to say hello. At this point I'm sitting in the same spot for most of the day and it's like 10pm and the mall is closing. I got up and started walking home, 30 minutes into the walk she sends a text that she won't be able to make it, I tossed my phone into the river. She never tried contacting me again, and when I saw her like 2 months later she didn't even acknowledge my existence.