I'll echo what others have said!
Pre-Unity VH1 are among the very best comic book stories from the entire decade of the 1990s. I'd honestly put the first four issues of Magnus, Robot Fighter ("Steel Nation") in strong competition for my favourite story from that whole time period. It's really that good. Once Jim Shooter was forced out, the quality wasn't as good, but as stated the BWS Archer & Armstrong were excellent and really anything BWS did for Valiant was either really fun or really awesome (Solar Alpha & Omega) ...or both!
X-O Manowar #0 - chromium cover and all - has a really enjoyable Joe Quesada/Jimmy Palmiotti drawn story.
As per @CKB, Valiantfans.com is the place to go for all things Valiant. Brilliant resource. My VEI reading - all of Robert Vendetti's X-O Manowar was great. Dysart's Harbinger as well. And since Jeff Lemire starting writing Bloodshot it's been among the best books that show up at my place every month!
Good luck and enjoy. Once you go Valiant (even I've stopped following Shooter's commands of all-caps VALIANT, all the time!), you'll be hooked!