What is a good synonym for "interesting"?

What's a good synonym for the word "interesting" or "interested"? I find that I use those words a bit too often (e.g. "I'm definitely interested!", "Yeah, that sounds really interesting, I would love learning more about it!", "That's interesting!", etc.)... but I can't seem to find any good synonyms. (Online sites don't really give me good synonyms.)

Any ideas?

Well. Here are a few that might be apt in specific situations. But remember, it is the situation and your comfort with the phrase that works best. Do not try too hard to not sound redundant. Nobody cares about too much redundancy in spoken english.

I'm definitely interested! = Count me in; You have my attention go on (from my boss)

Yeah, that sounds really interesting, I would love learning more about it! = Sounds pretty cool to me; Goodness me, is it true;

That's interesting! = Oh Cool...; That's fantastic; That's awesome

And how about these??

"I'll keep that in mind" or " I am going to make a mental note of it "

Though it's not a 100% fit -- you should be prepared to learn more if your response is followed up on -- I find that intriguing works in many such situations.

How about 'thought-provoking', 'compelling', or 'problematic'?

You probably want to stick with simpler words to express approval or interest. Words like cool, great, sweet, awesome, etc., are fine slang expressions to indicate interest but can even be used in a non-committal way.

Edited

For "I would love learning more about it" you might also say

• "That's worth looking into".

For "I can't find my glasses -- that's interesting"

• "I can't find my glasses -- Oh, that's weird!"