Quote Originally Posted by Kyna
Make it clear that his efforts make you happier, and not just "well its about darn time", because there is no positive feedback there. If anything its a backhanded compliment if that, and thats in no way encouraging. I find my guy will do just about anything if he thinks the reward is worth it.. and ultimately guys want us happy to make them feel successful in the relationship, no? Start little, baby steps, cleanliness is a habit, not a personality trait. Start with having him help you, involve him... make it fun, make it playful.. make him realize that helping you is rewarding to both of you. Granted you can't make people do 180's but change IS possible. Like someone said, people *grow* in relationship, just gotta make sure its in the right direction.
Good luck!
So much good advice already. I do have to agree with Queen and strongly disagree with bicam but...

Now that you've vented in the right place, a few points.
1 You already know yelling doesn't work. Neither does withholding. Withholding love or speech or anything else always ultimately backfires and pushes your partner away.
2 Of course people can change. They do all the time. The way to help a partner change in a positive direction is with specific instruction. Saying "help me clean up" is not useful. You are more likely to succeed with I statements with clear instructions. Such as "I would feel appreciated and happy and not taken for granted if you would put all of your dirty clothes in the hamper as soon as you take them off". Then when he does it he must get rewarded. This truly works. Remember to use small steps. Real specific easy instructions.
3 I've said it before, but I recommend "imago" to deal with relationship issues. A therapist or a weekend seminar is better but you can start with just the book. The book is called "getting the love you want" by harville hendricks. Some of it is goofy, but retraining yourself to ask for what you need in a polite and respectful way, including why you need it and how it would make you feel, followed by clear gratitude when it is done is the way to go. Everybody has annoying habits. You should also encourage him to tell you the things he's been "ignoring" about you. You probably don't even know what they are and how important they are to him.

Good luck