I echo the advice of others to let these items go. I like Carla's litmus test. You look SO amazing in that navy dress. All occasion wear should be up to that standard. Keep only things that make you feel great.
Having said that, I can empathize. I kept a number of items in my closet for longer than I probably should have and only got rid of them recently.
Having just lost significant weight (35 pounds) right before I joined YLF, I was at my lowest adult weight when I made my first YLF-related purchases. I maintained the new weight for about four years but then high stress levels got in my way and I regained about 10 pounds -- returning to what had been my former (pre-weight gain) set point. Then, this past summer, I lost about 5 of those new pounds. So much like LisaP, I now find myself betwixt and between.
If I'm honest with myself, this is my more comfortable and sustainable size. I know that even if I stay this weight, I might lose some extra cms. once I'm weight training again more regularly, and that will affect how things fit. But the truth is, I will want new things at that point anyway.
I do think ill fitting items taunt us and make us feel guilty if they're hanging there. Letting them go can be liberating. You don't have to live with guilt.