Alright, I'ma give my two cents here:
Splat Zones- Always my favorite. The perfect KOTH type mode that takes turf to a competitive level. Everything's about turf here. Spray the floor, and take control. Spray the walls, and hide in them! Also, attention is always brought into the Spat Zone, that's the "blood bath" of the mode. So you can really easily slip through the sidelines and flank the enemy. (Octobrush Nouveau anyone?) All in all a really solid gamemode and easily one of my favorite takes on King Of the Hill I have ever had the pleasure of playing in a shooter. This is also the gamemode I have the highest rank on. When it's running, I'm always sure to play a match or two.
Tower Control- Hey, this is the "Payload" of Splatoon essentially. A Giant tug of war over a moving cart that spans the whole map. This gamemode is always moving and always exciting, so the battle's always flipping back and forth and back and forth rapidly. This tug-of-war lasts a while too, it never feels like a perfect push to the end. I've played a lot of games where the match goes into Overtime. It's tough and always keeps you on-edge, but there's doubting it, this gamemode is a hell of a lot of fun.
Rainmaker- Eh....I'm still not in love with it. I've never been a fan of "Capture the Flag" in shooters, so there's a lot this mode has to improve over the traditional formula. Having the "flag" be a weapon sounds like a great balance: In a game without voice chat, being able to support yourself with the flag seems like a perfect solution. However, it's still not enough. The rainmaker is very weak and has a long charge time. This thing was better when I was knocking Octavio with this. You really have to count on your team, and when you get the rainmaker, they never defend you. Even worse? Teammates won't even pick up the Rainmaker! They all stand around it, shouting "Over Here!" until one unlucky player picks up out of obligation. And yes, that unlucky player is always me. I'm a C- here, fittingly.
Clam Blitz- Oh man. This mode was a nightmare at first. A true, messy, unclear nightmare. But after a week of playing it, it started to click, and now I can say this is one of the most satisfying modes Splatoon has to offer. It's complex, but different enough to offer something unique. It's also very independent, which is perfect for Ranked. You can support your own by running around, grabbin' clams, and blasting the enemy. Teamwork makes for a great push towards the enemy, but it isn't necessary. Whether the map is inked your hue or not, whether your team is lousy or pro, as long as you can quickly strafe around the map and get to the goal, you're golden. I'm still C Rank, but hopefully I can rank up soon as I'm really enjoy Clam Blitz. I personally think Mako Mart is where the gamemode shines. if you haven't played Blitz on Mako yet, you owe yourself some more matches!
All in all, Ranked is alright. The gamemodes are all fun and unique, the only real true downside is the lack of voice chat. Personally I will always play these modes on League or through Private Battles, since those allow for VC. But with the exception of Rainmaker and some TC matches, you can usually support yourself to a decent level, if your team's lousy. Out of everything Splatoon has to offer, being Octo Canyon, Salmon, PBs, Turf, League, etc, Ranked is actually at the bottom of my list. It's not that it's bad. It's just flawed, and the lack of communication makes the matches a tad messy. Still, if you can get around a sometimes bad team, there's still some truly unique and fantastic gamemodes to play.