I used Thunderbird for many years and I never really found it a problem that the newer messages are at the bottom. You get used to it. I settled on Thunderbird 2.0.0.24 and never upgraded further. Newer versions started to bloat and didn't support the one or two extensions I used. Very robust program!

I always had Gmail running behind the scenes, and actually Thunderbird was just downloading from there via POP3. However since I had a good Android phone, I've dived more into Google stuff... Contacts, Calendar, Tasks and Gmail. Now I've pretty much dumped Thunderbird and I've spent more time setting Gmail up nicely with labels and stuff from the labs. I can definitely recommend it, and I won't be going back to Thunderbird.

For Firefox I can recommend the extension "Gmail panel", as well as "Integrated Google Calendar" and "Gtasks panel" by the same developer.

p.s. I even flirted with Google Chrome for a while, but back in Firefox and happier now.

Since you don't seem to like Windows Live Mail 2012 you probably won't like the other Microsoft offerings, but have you tried the Mail client that comes with W8? Also, Outlook.com is quite powerful. They both look like Outlook, so if you don't like that look, you won't like these. I use all 3 on my laptop, mostly out of curiousity, but if you use a Microsoft account to sign in to Windows 8, which is really the way to go, then they all can work together fairly seamlessly.

depends whether you want local client on one computer or cloud?

i moved from thunderbird to outlook.com simply because i can now access my mail on any pc at any time. in the office i use the wlm client - i find gmail's organizational approach to categorizing and storing complete incomprehensible - a folder is a folder and their idea of tags and such like just doesn't cut it for me....

I abandoned local email clients completely. I use Yahoo, Gmail, and my ISP email for various levels of traffic and privacy. Biggest advantages are, I'm not accumulating all that stuff on my hard disk, and having the junk/spam prefiltered is better than receiving it locally, and I check my spam folders every weekend by habit.

i find gmail's organizational approach to categorizing and storing complete incomprehensible - a folder is a folder and their idea of tags and such like just doesn't cut it for me..

I agreed with that in the days when I relied on hundreds of folders in Thunderbird to organise my emails, but actually you can think of Gmail's labels as folders. The "move to" icon above an email even looks like a folder. The way to do it is to set up a label for anything that you think you might need to find in the future, but might not be able to find via a search for either the content or sender. So I have 13 labels set up such as "RF Media Purchases", "Customers Licensing" and "Distributors". I've found I don't need more than those 13. Most stuff you can just let fall into the general pool because the search functionality is so good.

Up to now I've been using Windows mail (Vista) which was very similar to Outlook/Outlook Express. I have 2 business accounts, as well as 1 personal, and another for Internet shopping - all the resulting spam then gets sent there. I also use Gmail.as a business account. Windows Mail took care of all of those easily. I can use 'cloud' options for all of those, but that means signing in to each one individually - tiresome to say the least. Also, I've turned off all of the 'cloud' spam filters after experiencing lost business emails from clients. That could kill a business. With Windows mail, one click on the Spam folder every now and then kept it easily under control.