usually in a conversation, we say"不错啊"or “听起来不错啊”. for me the first one would be more natural. and also some time we would say "好主意" which means good idea.

好主意or 听起来不错——表示同意，非常赞成！：）

听起来不错。 听起来很棒！

1.好办法 2.办法不错！ 3.好主意！ 4.主意不错！ And so on !

你好，咱们一起练习口语吧，我教你中文，你教我英文。我的skype是：zhang_hongchun999888