Kidou Senshi Gundam Seed Destiny

If you do not get beaten at all in the first 5 battles, Astray Red Frame will come out as an "emergency" gundam to fight you in the 6th battle.

At the Ending Credits of Main Mode Mission (Any Level from Normal to Very Hard). press start then press A Button repeatedly till you see a number in the bottom right corner of the credits adding up. Every 100 button pushes gives you a added bonus to your shop points.
My highest is 326 A Button Pushes. I got 600 points total. Whats yours?

Occasionally when you go into the shop, you'll find Cagalli in her blue 'formal' dress.

However, if you repeatedly enter and exit the store, the background will go purple and the shopkeeper will be Azrael. Instead of the usual items, he sells the unlockable mecha (Gold Frame Mina (Amatu), Astray, Freedom, Justice, Saviour, and the final boss, Legend, I think) for 10000 points apiece.

Also note that the next time you enter the shop, the shopkeeper will be Lacus again, and she'll be wearing the pyjama top from Phase-Ten of SEED and looks rather out of it. (oh Kiiiiiiiira! You have some explanin' to do...) She'll nick off and change into one of her five outfits and the usual shop will be open for buisness again.

You can repeat this as often as you like.