Your happiness now could turn to regrets later...
I'm sure you have good reason to feel that way but you need to remind yourself you might not feel that way forever. Allow yourself these feelings this season, for the reasons you have, but keep your final judgement on hold and reach out, even if it's just once, to your other grandma in the coming year. You may discover a relationship that you can develop and treasure. If not, you can comfort yourself that you tried, and that is good for your self-respect.
Your feelings are your feelings. Personally, I'd feel sad that I didn't have a better relationship with her, but not guilty for being happy to spend your Thanksgiving with someone you enjoy more. I hope you are able to let go of this part of things and have a great holiday!
You can choose your friends but you can't choose family...
My grandparents have all passed away now and I wish I would of spent more time with them !
Just enjoy the day. You don't have to like your relatives but sometimes you have to spend the holidays with them! Yikes.<br />
Just remember to give Grandma another chance at some point in the future. Sometimes you see people differently at different times in life. It won't hurt to try.
I'd give anything to have one more Thanksgiving with either of my grandmothers, yes I too liked one more than the other but did not hate either. Everyone's situation is different, but one day she will be gone and you might regret not spending time with her.
Don't feel guilty, just enjoy your holiday with the people you care most about.