Advice Needed Whats the BEST Forum Script to Use on Underground Forum? (was with phpBB2.x)

Hey Guyz/Galz, I was using phpBB2.x years ago (has great Themes for 'Underground' category, lots of darker themes back then)... I had the PHP/Code down pat, I knew where everything was to edit all parts of Core, Plugins & Templates/Theme...

NOW I have to start again, I started with myBB on one of my Forums (Collaborative Efforts with old forrst.me members = wen it changed owners and idea behind community, a few of us left to start a new HELP Community for Development instead of just another 'Show-Off Community' we went to Forrst core in helping ppl with code problems ie. when something wasn't working on a PHP function for eg the community would help pick out bugs, add to code, even write lines to work quicker/better etc for novices to LEARN (this was idea, and find ppl to collab with on good ideas)....

So after our Servers got sold to a U.S company, they re-sold the company with all our servers and LOST ALL DATA/Backups they had... SO STARTED/STARTING AGAIN :-(((((
The above is how we started a NEW KReW of Awesome People to build a Network of contributor's behind [for variety of skills for different types of Sites, WebApps, Web Services & Communities [I added all this so you know where i'm coming from, as to best Script for Forums to use, so can learn as we go as in Development Team to Customize over time, Write Plugins, Expand by using pre-existing plugins/mods ie. who has best etc... eg. V.i.P & a Marketplace is one of 1st acts of business for 3 different types of Forum Categories, though all needing base core functions ...

but NOW, Starting from Scratch, and I was working on a Forum with myBB myself while others better at coding took care of other main scripts behind some core sites/WebApps... AND I Re-Upgraded the same myBB 1.8.32 as i thought I did something wrong, as the Theme was not updating i thought, and misread theme instructions that myBB needed to be Updated to Latest Version for some of the features to work, and didn't know I couldn't UPGRADE TWICE with same version,(this lead to 500 Error in AdminCP after Login Box).... still not sure if i should risk using the mySQL DB backup and do fresh install (will it keep ALL Data/members/forums/threads/posts??)[i understand i will need to re-install plugins, but was only a few minor ones i can re-do anyway (as i was still learning my way around plugins to write our own)???? [This is great help, as i'm stuck atm, and i'm happy to use myBB for this particular forum is fixable]//
ITS THE OTHER FORUMS/Communities I'm Trying to Pick BEST OVERALL Software/Script/Plugin Design FOR, GUYS...

ANNYWAY-> To my Question.... What is Best Forum Script to Use Guys (I'm Fresh to all of them these days, last forum script I used I stuck with v2.x of phpBB as had it Customized beautifully.... I'm thinking myBB, XenForo, phpBB (Latest)... (open to others)... WHAT is UR GUYS/GALS OPINION? .... And WHY Pls???