你去哪儿了?
Where have you been?

很高兴又见到你。
I'm glad to see you again. *回答这句时说So am I. (我也是)。see可以用meet代替。去掉again则带有初次见面的语感。
I'm happy to see you.
Nice to see you.
It's great seeing you again.

你一点儿都没变。
You haven't changed at all.
You're the same old Bob, aren't you? (鲍勃，你还是老样子。)

你没怎么变。
You haven't changed much.
You haven't changed much. (你没怎么变。)
Neither have you. (你也没变。)

你变样了。
You've really changed.

你长大了。
You've grown up.
You're all grown up now.
Look how you've grown up. (看你都长这么大了!) *多用于爷爷、奶奶见到孙辈时。

你越来越漂亮了。
You've become so beautiful.
You've gotten so pretty.