Please post here the (really) usable alternatives.
By usable I mean:

- You don't loose funcionalities
For example, if you run only Android, you can't call, but if you run easy debian WITHIN the maemo, you have all maemo functionalities plus debian ones.

- You can really use it
It's not laggy or makes you think "uhm... something is not right";

- It worth tryin'
You got some cool apps that you can't have on maemo itself.

That's a good thread IMHO, since it cleans the forum. So much talk, time is money!