Start where everything connects
Sukhumvit (Asok / Nana / Phrom Phong)connected Bangkok
For first trips or when you want Bangkok to feel easier to navigate.
This is where Bangkok becomes easier to handle. BTS access changes the whole trip.
Asok gives you both BTS and MRT, which makes it one of the most useful bases in the city.
Nana is busier and more nightlife-heavy. Phrom Phong feels cleaner, more polished, and more comfortable for a slower stay.
You are not choosing the most atmospheric version of Bangkok, but you are choosing one of the most practical.
For a first visit, that trade-off usually works.