The first two countries that come to mind for me are Israel and Poland; two countries that understand better than most that freedom and liberty cannot be taken for granted.
I'm glad that Poland is a full member of NATO.
I think may of the US's standard allies are less happy with Trump because he publicly expresses our expectations of them to hold up their ends of alliances. Most have lost their fear of oppressive adversaries and think that our alliances are more important to us than they are to them, so they cash in on them. Trump is righting those relationships and some (mostly establishmentarian) governments are squealing.
Russia is clearly no ally of the US or Trump; he is making their lives miserable militarily and economically and Putin keeps puffing his chest to try to show Europe and the Middle East that Russia is still relevant. But it isn't other than what it has bottled up in its silos.
Saudi Arabia is a worthy ally because keeping Iran in check is more important than telling Saudi Arabia how to run its own internal affairs (something liberals usually criticize our government for doing). Plus Europe and Asia really count on that Middle Eastern oil, and frankly none of the affected countries have the wherewithal to protect their own interests. As usual they count on the US to do it for them.