The reason I mentioned Renekton is that he seems to be about as mobile as Fiora with a fairly well-rounded kit for a bruiser.
Gangplank, from what I've seen, builds damage almost exclusively, but his barrels tend to keep you pretty safe considering his biggest downfall of being (technically) melee.
Vlad is someone I can talk about a little. He's a mid/late-game monster. His goal in lane is to simply out-sustain his opponent with his Q. His E costs a decent amount of health early, so try to hold off on using it until a little later in laning phase. I usually don't use it until I get to around level 4 or 5 because by then my Q heals it back and then some. Also, don't even bother getting your W until at least level 3. It costs 20% of your current health to use and is only really good defensively unless you're way ahead. As for a build, you want a Will of the Ancients first and a Spirit Visage second. These two items were MADE for Vladimir. After that, you can stack health or AP and you'll deal damage and get tanky either way. More damage stacking AP, more tanky stacking health, but they both play off of each other anyway, so you'll go both ways stacking either. One is just more damage, the other is more tank. His ult is simply amazing to have late because it amplifies damage taken by whoever is effected by it by 20% for something like 6 seconds. Beautiful.
Fidd hasn't changed any. He's always been kinda useless without his ult and he's not versatile at all. I just brought him up because of his ult specifically.
Mundo hasn't changed, either, but the masteries have. The new masteries made him pretty busted. You almost can't kill him when he has his ult, so he's fantastic for...About anything. The problem is that he is the single most banned champion in the game at 74%. Add that to his play rate and he's involved somehow in 78% of games with a ridiculous win rate at 54%. That's the 2nd highest win rate only topped by one of his highest counters - Trundle. Dr. Mundo statistically one of, if not the easiest champion to play, also. With his playerbase in ranked having an average of 12 games on him. This is why I referred you to him. He's easy to play so you can focus more on game mechanics, he's got a high win rate to keep you satisfied with the game, and he's relatively cheap to get. I think he costs 1350 IP.
Champs to stay away from would be:
Azir. It's pretty agreed upon that he's the single hardest champion in the game and while he's very fun to play (IMO), being on that level of difficulty might not be a good idea for people starting out. I'm going to repeat this over and over here, but learn the game before you learn this guy.
ADCs in general. While they are some of the easiest champions in a mechanical aspect, the way they have to play mid and late game makes them probably the hardest ROLE in the game. They are everyone's target and because of this, you have to have a good idea of where to be in fights. They're a necessity in any team, but perhaps not a good idea until you get to observe a little of what they do and how they do it. You should learn it, definitely, but maybe not immediately.
Lee Sin. Like Azir, he's pretty rough to play starting out. He's got a higher win rate and he's the most played jungler in the game right now, if I remember, but again, he's mechanically challenging, so you might want to focus on an easier champion to learn the jungle before you try to learn Lee Sin.
Riven. I've never personally played her, so my insight is limited, but from what I've heard, she's another champ where you should learn the game before this champion. She might be one of the hardest top laners to learn simply because of the way she plays, but when you do learn it, get ready to carry the fuck out of games.
You seem to have your main role picked out in top lane, but you should try to get somewhat of a grasp on other roles just to learn a bit of how the game works. Also, if you find one particular champ a nightmare to play against, play that champ for a while and learn it's weaknesses.
"It is said that if you know your enemies and know yourself, you will not be imperiled in a hundred battles; if you do not know your enemies but do know yourself, you will win one and lose one; if you do not know your enemies nor yourself, you will be imperiled in every single battle." -Sun Tzu