Mass Effect 2

If you chat it up with Yeoman Kelly Chambers often and choose to be kind to her you can instigate an "unusual" romantic encounter. You'll eventually be able to invite her to dinner. Additionally, you cannot let Kelly die in the final mission (choose a loyal escort for the crew in the final scene). After you beat the game, talk to Kelly and you'll receive an email from her. Go to your quarters and you'll be able to invite her up using your console. She'll appear and you'll be able to watch the evening's awkward events unwind. She's no Yeoman Rand, but she'll do.

Recruit Morinth to get the Dominate skill and get a large amount of Element Zero. Purchase the Advanced Training upgrade and choose Dominate. This result in a bonus skill point, which is then used by the Retrain Powers upgrade. Repeat this process to get another skill point.

While evolving a skill to level 4, press A + X to regain all spent squad points and keep the skill evolution. This works best if you level a skill from 0 to 4 (10 points) in one go.