Myestry In Tanak:
1. Adam, G-d's first creation failed in his purpose and was driven out of the garden
2. Abel over Cain (Genesis 4:1-7 - G-d disapproved Cain's offerings, after Abel murder Seth was chosen and Noah descended from him.
3. Shem, the son of Noah was younger that Japheth (Genensis 10:21)
4. Issac over Ishmail (Genesis 17:15-19)
5. Jacob over Esau (Genesis 25:23, Malachi 1:2,3
7. Joseph over Reuben (birth right - Genesis 37:5-11, 45:8, 50:20)
8. Judah over Reuben (Genesis 49:10 - Royal line, Kings including David)
9. Levi over Reuben (Preisthood, Tabernacle ministry)
10. Perez, son of Judah over Er, Onan and Selah (King David's ancestry)
11. Ephraim over Manasseh (Genesis 48:20 - When Jacob blessed Joseph's sons he laid his right hand over the younger grand son)
12. Moses over Aaron to lead Israel (Exodus 7:7 - Aaron 83 years old and Moses 80 years old)
13. Kohath over Gershon - Moses and Aaron descended through Kohath and not from Gershon or Merari
14. Eliezer over Nadah and Abihu to continue the priestly line of Aaron (Leviticus 10:1)
14. Gideon (Judges 6:15)
15. David over Eliab (1 Samuel 16:1-13)
16. Solomon (1 King 1-2)
Biblical scholars also believe that Noah and Abraham were younger sons!
Well, there might be some personalities in the Bible who were first born but the Tanak does not explicitly mention G-d choosing an older son over an younger son as in the case of Ephraim over Manasseh.