Gemini + Virgo
Virgos are famous for their practicality and rational approach to everything. Gemini has those traits too. However that's where the commonalities end, because twin's approach to life is based on the idea of enjoying every day to the fullest, which means adventure and trying out new things. This does not fit so well with cautious virgin, who loves stability and consistency. There will be many fights due to this difference, and the only way out is adjustment and flexibility. Not the best match, although its success depends a lot on how much each is willing to adjust.