Believe it or not, I play my game mostly vanilla except a few tweaks.
There are good mods all around the web, I'd recommend you to check out Not AJ's YouTube channel if you're interested in other mods specifically for your game version. As all the mods I'll suggest were used by myself only on 1.0.4.0.
This is my personal recommendation, you might not agree with my choices of mods but that's the magic of modding. Make your own or download something else, nothing can stop you!
Thank you.
Realistic Driving by Killatomate
Fixes the driving physics that made cars feels floaty. Makes driving more fun to me, I know it's blasphemy for some but I've been using this mod since its creation and I love it as much as when I first tried it.
Download here at gtagarage.com
RevIVe Trees by BisonSales
BisonSales has been working with me since iCEnhancer 3, he started RevIVe to improve what he believed could make the game look much nicer and run faster. I highly recommend his public version of the vanilla trees which improves the overall look of the trees without any performance impact.
Download here on his Discord server
Immersive NY by Vex (joemoo) and Nariman
Crazy hard work from Vex & Nariman recreating many parts of NYC into Liberty City. Building textures, models, billboards, decals, props, etc, have been changed while remaining a look that is "lore-friendly".
Check out the full list of changes in the mod project link.
Download here at gtainside.com
Zolika Mods by Zolika1351
When I came back to modding back for iCE 4, Zolika1351 out of nowhere fixed decade-old issues with their ZolikaPatch way before anyone even figured out how to fix them.
ZMenu has now replaced SNT on my end. I spent most of my GTA 4 modding "life" using Simple Native Trainer but switched to ZMenu entirely.
A bunch of other mods (Compatible with versions newer than 1.0.4.0) are also available on their page.
Unfortunately, Zolika has now left the modding scene and no updates will be made on the mods available.
Download here at zolika.dev
For more mods ?
At the time of writing this page, I honestly don't remember what I used to install in the past. I do remember better gun handling mods but no clue which one it is.
To check out older mods that will surely work with 1.0.4.0, check out the archived GTA4-Mods.com page which was the best GTA4 modding website at the time.
Gta4-mods.com archive link
If you prefer the vanilla look of the game, simply install whatever you feel like. The game has so many versions and mods and variants created since its PC release, just don't be worried about looking for an outdated mod. They still work fine. Have fun.