Its an excellent series, and whenever we got a new character included in the roster they always felt unique and really fun to play. Heck, I remember being jazzed that Takarashi was added back into VF5 FS. Plus the game never needed meters, comeback mechanics or anything like that (which is fine for a wacky game like Street Fighter or KOF, but more and more games are adding this and I'm not a huge fan depending on the game, Tekken 7 does it well though).
The series is just pure fighting bliss, Lau will always be my favourite, especially in later games thanks to some simple yet fun combos, though it was Judge Eyes that really got me into more characters besides him as I played through the game with everyone, and ended up being really surprised at certain characters (ended up loving Aoi, which I never thought would happen). While its definitely not a simple game to master, its still simple enough to pick up and play and enjoy, after learning a couple of simple-ish combo's I was on my way to funland! Oh, and VF4 Evo and 5's Xbox ports have excellent single player content with their challenge/world tour modes.
Only real criticism I can level against the game is what they did to Vanessa post VF4. I loved her design and appearance in 4, but they reduced her muscles to make her look more feminine? And not to mention changing her skin colour for absolutely no good reason. VF5 gives her a far lighter skin tone than what she had in 4 and it still annoys me to this day.