The $5s are really hard to rank, imo. I mean, even the cards on the last ranks aren't really bad, rather situational.
Concerning the concrete rankings:
CH is certainly not a great $5, but imo worth it not that rarely. I've seen it put to good use in Ambassador games, for example, and the $ generated by it is not that bad when compared to say, Harvest. I don't think it's the worst $5, probably not even in the worst five $5.
I would also have rated Saboteur a bit higher. It can turn games around with a bit of luck, when you're desperate.
I pretty much agree on the rest, although i would have switched the rankings a bit.
Edit: Yay for the rankings going up!
But then which cards would you say are worse? I agree Counting House and Saboteur have their uses, every card has its uses, but which cards have fewer uses?
Well, I don't really know the DA cards, so can't comment on them.
But I can see myself rating Harvest (imo the worst $5), Mine, Contraband, Cache and Stash below CH and Saboteur. Maybe Explorer too, but I probably underestimate that card.
I think that CH and Saboteur more often have a dramatic impact on the game than those other cards I mentioned, and that often CH and Saboteur are disregarded prematurely (this does not make them "good" $5's in most cases anyway, and I'm pretty sure both belong to the worst ten $5 cards overall).
In fact, I would rate Tribute below CH and Saboteur as well. That may, however, be a personal issue, as I just dislike buying and using this unstable card which relies so much on luck. You don't know what you will get, you can't choose anything, and usually options range from +4 Actions over +4 Cards to $4 (all of which sometimes great, sometimes horrible). You can even be so unlucky as to draw two same cards. Such a random effect is not what I want when I play a card, especially a $5 card.