You're almost there! Of course there are a dozen ways to phrase something so typical in either language, but to follow the same vein as yours (which is perfectly fine!) I would suggest
Ba mhian liom... I would like to watch a movie tonight... because you are describing something that will happen in the future. I'm not actually sure how best to explain the difference between English and Irish here, because in English you are announcing how you feel at this second. I think it's because in Irish you are addressing a feeling that, though felt presently, is describing a feeling that might/will be felt later.
HAHA. I'm not sure how clear that was. Maybe someone else can explain it more precisely, or even correct me

Either way, I'm confident
Ba mhian liom is correct - it's what I'd say in speech.