Adding on to what Emiko stated,
Other competitive decks don't need to be what is considered the meta today, or tier 1,2,3. Any deck can be competitive as long as you have the right tools to stop and eliminate you're opponents deck.
Current top Competitive decks or the meta are as follows: Inzecktorz, Wind-ups, Chaos Dragons, and Dino Rabbit. I will explain why each one is currently considered the meta.
First off is inzektors, my personal hell, this deck focuses on the constant summoning and equipping of monsters with the "inzektor" name. The top contenders in these decks are inzektor hornet, inzektor dragonfly, and inzektor centipede. Each one of these monsters has the ability to destroy or special summon something. So watch out, they are hard to beat without a veiler in hand, or vanity's fiend on field, etc.
Second, Wind-ups rely alot on the same thing as inzektors, except they don't equip, just swarm the field faster than you can blink. This deck moves a little slower than inzektors, but is still capable of an otk with the right cards so be careful. I have a lot less info on this deck, i've never faced it, only watched it partially.
Chaos Dragons, my realm of play, this deck in my opinion is the best of the current meta. You can OTK (one-turn kill) more times with this deck than any other (except for maybe exodia but we don't count them). The main contenders in this deck are red-eyes darkness metal dragon, lightpulsar dragon, chaos sorcerer, and of course black luster soldier- envoy of the beginning. My version of chaos dragons uses lightsworn lyla, and ryko as the engines for discarding. Plus a card trooper. you will see many sacrifices to the grave just to summon lightpulsar, sorcerer, or BLS. The main way to stop this deck is dimensional fissure. Uses very little to no traps, and just staples for the magic.
Finally, we come to dino rabbits. The goal of this deck is to bring out Evolzar Laggia or Dolka or both, as fast as possible. They will usually bring out kabazauls with rescue rabbit's effect, then xyz into Laggia or Dolka. Be careful when they get Laggia or Dolka out, because each come equipped with their very own surprises. Laggia is a summoned solemn judgement, without the cost. Dolka can stop any effect connected to a monster card with just one material loss. Veiler is your best friend against this deck, or Thunder King Rai-oh
In this add-on to the lesson i explained why these decks are competitive, and how to beat them, now go out there and find your combination that can beat them without being them. Stay focused and stay creative.
Zer0st0nez