Honestly you can watch them any how you want since a lot of the series take place in difference universes, timelines or different POVs for example the One Year War has like (MSG, 8th MS Team, and War In A Pocket).
I prefer the Gundam series without that super ability shyt

So Gundam Wing and 08th MS Team were my shyt.
But back to your question I don't think it matters how you watch them. The only ones you can probably watch in chronological order is the Universal Century and it goes like this:
1-Mobile Suit Gundam MS IGLOO (January, UC0079)
2-Mobile Suit Gundam (September, UC0079)
3-
Mobile Suit Gundam: The 08th MS Team (October, UC0079)
4-Mobile Suit Gundam 0080: War in the Pocket (December, UC0079)
5-
Gundam the Ride: A Baoa Qu (December, UC0079) *Amusement Park*

6-Mobile Suit Gundam 0083: Stardust Memory (UC0083)
7-Mobile Suit Zeta Gundam (UC0087)
8-Gundam Neo Experience 0087: Green Divers (UC0087)
9-Mobile Suit Gundam ZZ (UC0088)
10-Mobile Suit Gundam: Char's Counterattack (UC0093)
11-
Mobile Suit Gundam Unicorn (UC0096)
12-Mobile Suit Gundam F91 (UC0123)
13-Mobile Suit Victory Gundam (UC0153)
14-
G-Saviour *Live action television movie*
The way to watch After Colony Era is like this:
Mobile Suit Gundam Wing
Gundam Wing: Endless Waltz (film)
I ain't bout dat life...
I put the ones I watched or thought were worth watching in bold.