Interesting that all the Churchill suggestions are getting dislikes, his speeches alone...
I find the love for Hitler a little unsettling conversely... Post 1942, where arguably you'd need him to be the most inspirational he could be, he's lost his nerve (no public appearances, the drugs start post Stalingrad). Sure, he got the country moving and back on track (to disaster) but when you needed a Churchill figure in Germany to rally the troops and do the whole "we will never surrender" for the Germans, he wasn't there.
Stalin... I think Stalin's a better leader than Hitler, but not more inspirational. There's a few significant moments... but he spent the rest of his life trying to make himself out to be an inspirational leader, he probably had Churchill envy. The only significant moment for him personally where he is one show from memory is in his speech a week after Barbarossa, but what made that speech important was that it was all about defending Russa, not communism...
I don't know enough about FDR to comment on him.
Now... what about commanders? What about some inspirational commanders. Slim might be a good candidate for that, but I'm sure there are others. I'm most familiar with Soviet commanders who generally went in for more violent forms of encouragement than inspiration.
I do find Rokossovsky quite impressive, but not for being inspirational but for fighting exceptionally for a regime that had taken out all his fingernails and kicked out his teeth.