I liked both but I felt like the second movie 'Cardcaptor Sakura: The Sealed Card' was more interesting and inspiring.
I liked how the 1st movie showed Shaoran's side of the family and how the ending went (which was both sad and beautiful).
For the second movie I thought the story went more smoothly and more interesting content-wise. Since the second movie was more of a continuation of the series, it felt more familiar and connected(?).
The Sealed Card. I find it very lovely and cute, especially the time when Sakura found her courage to tell her feelings towards Syaoran. Isn't cute???