How much would you appreciate your ex if he/she send you a gift of any sort?

I would send it back
Could care less of his intentions, he is a cheater
Selfish =- He is a jerk

Offended because he should have thought about that when he was cheating... Do I sound bitter?

I guess it depends on a number of things. If you're currently in a relationship. How serious that relationship is. And if your ex is aware of said relationship. If I was single I'd feel awkward receiving the gift, but I'd still accept it. If I was in a relationship, depending on the extravagance of the gift, I'd be either a little annoyed or very upset. Unless you're on very good terms with your ex (and even then it's iffy...), I think giving gifts is a bit out of line.