Well since everyone is doing it, I am curious to know which is the better Post-Apocalypse game in your opinion. I just started playing Metro Exodus again and am really surprised how good the game is. I enjoyed my time with Fallout as well.

Lets compare the mainline series (excluding Fallout 76)

Metro Series

Metro 2033

Metro Last Light

Metro Exodus

---VS---

Fallout Series

Fallout 3

Fallout New Vegas

Fallout 4

Personally I feel Metro holds the visual edge, its like the Crysis of Post-Apocalypse games while Fallout is more iconic as it has more Remembrall things in it like the Pit-boy and the Hazmat Suit. I slightly glide my decision on Metro as I do prefer the more linear story telling while it does lack the open world style and customizing that Fallout brings to the table. 

I assume you mean the modern Fallout games in this comparison, if we're talking vanilla wise with no mods then I'd give it to Metro overall, Metro has the better structure and execution in its story and such but Fallout is better in exploration and open world aspects.

With mods of course.

I dont like the direction they have taken Fallout games resently.... I'd say fallout is still a "bigger" IP, but quality wise, Metro might have it beat in future.

Fallout for it's lore, Metro for it's visuals.

Honestly Fallout had more going for it story wise, compared to Metro, where you had up to 3 different types of foes to go against, and a story that was rather self contained. I liked Metro/LL's stories, but compared to Fallout, they are quite small in lore/tales to tell.

Metro wins that duel

However, if it went up against Fallout 1&2, Fallout would have won hands down.

FO 1/2...though there were attempts to make something as good as those two games (Wasteland 2, UnderRail and ATOM RPG come to mind), they're, IMO, still uncontested in what they achieved (at least when it comes to video games).

As for newer ones. I'll take FO 3/NV over Metro Exodus (can't really compare them to Metro 2033/LL, they are more of a classic linear shooters), though I'll take pretty much anything over "FO" 4.

That would make for another good comparison between Fallout 1 and 2 versus Wasteland 1 and 2.

Metro. I could never get into Fallout Series.

Honestly, I've played Wasteland back in 80's on C64 and though I liked it, it didn't wow me (I don't know, maybe I was too much into D&D back then or something - I should probably replay it). But for some reason FO1 hit all the right spots, and FO2 just solidified the experience (I find FO2 to be better game, but FO1 is still my personal favorite).

Wasteland 2 was good, but honestly, IMO, combination of world building, characters, story, humor and atmosphere (in no small part due to superb soundtrack) in FO1/2 stands quite above it.