/vr/ - Retro Games

>>4819072
The most important Newgrfs are the trainsets, of course, so I usually start by picking a trainset I want and then build the rest of the list around it. Sometimes they have a clear theme and it's obvious which other sets will go well together. For example, the Japanese Trainset has a whole set of matching Japan-themed newgrfs that overhaul pretty much all of the base graphics. Other popular examples:
>Dutch Trainset - what it says on the tin
>UKRS2 - UK renewal set
>NARS2 - North American renewal set
>DBset - Deutsche Bahn, German railways
>xUSSR - Engines and rolling stock from Russia and ex-Soviet countries
There are also general trainsets that aren't specific to one region or country. These might be good places to start if you haven't used newgrfs before.
>2cc Trainset/2cc Trains in NML - An excellent set of interesting trains from all over the world
>Iron Horse - generic trains (i.e. not re-creations of specific historical trains), more similar to the default vehicles than other trainsets
Pay attention to track types. Some trainsets come with their own tracks, others expect you to load a generic track set like nutracks.

In addition to a trainset and whatever companion newgrfs it goes with, I always load a road vehicle set with trams (usually just eGRVTS), a planeset (even if I'm not planning to use aircraft), a ship replacement set like one of the FISH derivatives, and some eyecandy infrastructure sets like station graphics or pure eyecandy objects. I could post more details about non-train newgrfs if you'd like.

>>4739497
The JapanSet newgrfs are great, probably my most frequently used set. I recommend loading all of them if you are going to use them (trains, buildings, landscape stuff, signals, tracks, stations, etc.). After that you will want newgrfs for all the stuff JapanSet doesn't cover. Even if I'm not planning to use non-train vehicles much, I like to load newgrfs for them just in case I want to use them in some limited way (like a cute little ferry going to an island or something).
Trams are awesome, so you should always have eGRVTS loaded at a minimum, maybe some other themed tramset if you find one you like, but beware that the costs will probably not be balanced with eGRVTS.
For planes there's AV8 or World Airliner Set which are both pretty similar. Load one or the other.
For ships, use whatever the most recent variation of FISH is (Squid Ate Fish?).
Road Hog is a cool tramset that gives you industrial trams that are like mini-trains. They look cool at least.
I also strongly recommend a bridge set. TBRS is good and has a variant that matches the Japanset graphics.

In games where you aren't using Japanset, you will still want to load a trainset and an appropriate track set (2cc and nutracks for example), a bridge set, a station set, and probably a building/town/road graphics set. Many station sets (like the Japanese station set) just include passenger stations, so if you are also going to do freight you will want something like Industrial Stations Renewal (and the various DWE station/object sets that mesh nicely with ISR).

That's the practical stuff. I also like to load eyecandy, so I tack on pretty much every newgrf with "objects" in the name at the end of my list. My favorites are Dutch Road Furniture (which gives you cool-looking but purely cosmetic highways) and MariCo, which is very cool looking dock stuff (but you can't get it from the in-game content browser, the author makes you download it from his website for some reason).