Formal:
* قضيت عطلتي بسعادة (Qadītu `aṭlatī bisu`ādah) - This is a very formal and direct translation.
* استمتعت بعطلتي (Istamta`tu bi`aṭlatī) - This means "I enjoyed my holidays" and is slightly more nuanced than simply saying "I spent my holidays happily."
Informal:
* كانت عطلتي رائعة (Kānat `aṭlatī rā`i`ah) - This means "My holidays were fantastic."
* قضيت وقتًا ممتعًا في العطلة (Qadītu waqtā mumti`an fī al `aṭlah) - This means "I had a fun time on holiday" and is more specific about the enjoyable aspect.
Even more informal:
* ما شاء الله، عطلتي كانت حلوة جدًا (Mā shā'a allāh, `aṭlatī kānat ḥilwah jiddan) - This means "God willing, my holiday was very nice." It's a common phrase used to express gratitude and satisfaction.
The best way to say it depends on the context and who you are talking to.