Gouken’s main BnBs start with neutral jump FP, which leads into one of three main combos:
If you have ex meter:
nj.fp > fp > ex palm > dash forward > rh.tatsu
Notes: This is Gouken’s most damaging BnB, using only one meter, and will take about 45% life from the average character. (455 damage)
If you don’t have meter, and the opponent isn’t crouching:
nj.fp > mp > cr.lk > rh.tatsu
Notes: The reason these specific normals are used are as follows - mp is used instead of fp because tatsu will not connect properly after fp. cr.lk is used instead of cr.mp (which would do more damage) because cr.mp pushes the opponent too far away to allow tatsu to reliably connect. This combo will give you the most damage possible without using any meter. (332 damage) As noted, this combo will not work on a crouching opponent.
If you don’t have meter and the opponent is crouching, or if you simply want a very safe combo:
nj.fp > mp > cr.fp > lp.hadouken
Notes: Ending in a projectile means Gouken is completely safe on block. Lower damage than the previous two combos (273 damage), but works on crouchers as noted. MP is used because it can lead into cr.fp, which results in more damage than simply doing nj.fp > fp > lp.hadouken
Any combo that starts with neutral Jump FP -can- be performed from any hard attack jump-in, and also from a MK jump-in, but if the MK hits your opponent too high up, you will not have time to connect with FP after landing on the ground. It is more reliable to use MP instead of FP after MK jump-ins because of this.