...again?
I started a thread last year as I'd had two leaky mugs in a row and was wasting money trying to find the perfect travel mug that absolutely never leaks.
MN responses were great and voted for a lovely Avex brand mug. I bought it. Was perfect. DH washed it and lost the rubber seal. Now it cannot be used. The same one is no longer for sale and the manufacturer does not offer spares for sale. 
I can even find the old thread to see which mug came second.
So, what other travel mugs would you recommend? It needs to keep tea hot for at least 2 hrs and positively leak free! TIA