"好想出国留学英国"的英文表达是："I really want to study abroad in the UK." 或者 "I have a strong desire to go to the UK for further education."

如果你想要更具体地表达你想要去英国留学的目的，你可以说：

"I aspire to pursue my studies in the UK."

"I am keen on studying in the UK and gaining valuable experience."

"I am planning to go to the UK for higher education."

这些表达都能传达出你想去英国留学的强烈愿望。希望这些信息对你有所帮助!