For me (and probably most people) #1 will always be the RYNO II. 100 ammo, auto-locks, gets the job done, doesn't upgrade because it doesn't need to, and an awesome design.
#2 RYNO IV: I like this one a lot because it doesn't cost anything, it's upgradable, and all you have to do is eject the disc on Nundac Asteriod Feild, and BOOM! You get the weapon
#3 RYNO VII: Sure its just a rip-off of the RYNO V, but its actually better because of its aim, and design. And in challenge mode, they give you a golden RYNO, something I've wanted since the first game. You did well Insom
#4 The RYNO: Even at 150,000 bolts, this powerful missile launcher is well worth the wait.
#5 RYNO V: V at 5, ironically. This weapon is so popular, that it made it #51 on top video game weapons list. Still, it doesn't aim well; if they fixed that, it would probably be higher up.
#6 RY3NO (Rip You Three New Ones): This weapon fires like the Zodiac, but unfortunately, the HD collection screwed up the audio functionality of it, making it less enjoyable to use.
#7 RYNO 6 Protosuit: Probably everyone's last. While this seemed like a great idea, it was brief to say nonetheless (RYNO's from SM and SAC don't count)
"So we fix our eyes not on what is seen, but on what is unseen, since what is seen is temporary, but what is unseen is eternal."