LOL, there are SO many options!
Mostly, it depends on your vehicle size and type.
I'm running an almost new 31ft class C, so here is what I started with a few months ago stock OEM, and what I have added/modified recently to my Fleetwood Tioga 31W...And I will add that I am a single man that travels alone.
As shipped from Fleetwood stock:
0 solar
2 ea 6V 200 amp flooded house batteries
1 Onan 4000 Watt genset
30 amp shore/genset power connection into a cheap WFCO 8955 converter to operate the RV fully and charge the house batteries.
Bi-directional battery isolater between house and starter batts.
AS recently added/modified:
6 100 watt Eclipse panels
2 Blue Sky 3000i charge controllers in parallel to LifeLine batteries
2 shunts and 2 Trimetric battery bank monitors.
one 2000 watt PSW inverter with transfer switch and smart charger built in
4 LifeLine 225 Amp AGMs for solar bank
2 each Yamaha 2000 watt inverter gensets with parallel cable
1 Iota 45 converter charger with smart IQ4 built in to use as portable charger.
1 progressive Industries 4600 series smart charger converter installed in place of the old WFCO for the house batteries.
Soon to add:
4 more Eclipse 100 watt panels for house batteries
1 600 watt PSW inverter off house batteries.
1 Blue Sky 3000i for house batt solar system.
I am a retired nuc submarine sailor that seeks to get way way off in the boonies for very long periods of time and retain all the creature comforts possible....including in motion sat TV, roof top digital TV, extended wifi, extended cell phone, 70 gallons fresh water, one ton of food, and plenty of tools...SO I insist on a back up for the back ups.