My preferred top lane champions are:
Generalists
These champions are reliable and safe picks into most laning match-ups. Their sustain, mobility and burst damage provide strong trades in lane and let them hold their own against most opponents while snowballing with any advantage they can get. Their build paths are flexible and can easily be adjusted depending on the situation. One item of note is their ability to survive against and kill ranged champions during laning phase.
- An influential champion in the early- and mid-game whose mobility, burst damage and sustain let him bully and/or survive most lane match-ups. While he does fall off later in the game, items introduced during the Juggernaut update have helped mitigate this somewhat and keep him relevant as the game progresses.
- A mobile champion with strong laning mechanics and an extremely powerful mid-game, capable of diving the enemy carries and sticking to her target through the enemy's peel. Her burst and sustained damage and deceptive durability make her a powerful threat while her mobility and CC let her dominate opponents once she gets a lead (or survive against them when behind).
Anti-tanks/Disruptors
These champions are useful for fighting against and killing enemy fighters and tanks at all stages of the game, becoming extremely durable while dealing high amounts of damage to enemies. They tend to work well as split-pushers since they are generally strong at 1v1s and can hinder the enemy during teamfights.
- Trundle is one of the best buff/debuff champions in the game; he is capable of stealing an enemy's AD (weakening their trades) and their health/armor/MR for himself, both weakening the enemy tank/fighter and greatly empowering himself. He's a strong duelist and split-pusher while his passive sustain and buffs/debuffs make him very difficult to lane against. Also, one should not understate how useful and flexible his Ice Pillar can be when used properly, blocking off paths and disrupting/trapping enemy champions.
- Dr. Mundo scales extremely well with defensive stats and can quickly turn into an unkillable nuisance to the enemy team. His high innate damage lets him build pretty much entirely defensive items, so his durability and sustain (passive and ultimate) can him very difficult to shove out of lane after his first item is finished. His Q provides safe last-hitting, a chainable slow and potent harass while his movement speed can make him difficult to stop or chase down. Also, he's quite useful for early baron attempts. His sustained mixed and percent-health damage mean that he can be quite difficult to build against and that he's quite good at killing enemy fighters and tanks.
CC/Utility Tanks
Champions with high durability and utility who are still capable of surviving and trading in laning phase against most match-ups. They are especially useful options for when your team has multiple squishy carries (DPS mages, ADCs, assassions) and little else.
- An immovable titan who excels at initiating, peeling and locking down targets while slowly beating them to death with his anchor. Nautilus is a rather strong laner with decent damage, high durability and massive amounts of CC. I will commonly pick him when my team has multiple assassins and/or carries.
- Maokai provides a massive amount of utility in multiple forms while being capable of trading with most opponents.. He is deceptively durable during fights due to his passive (which will be procs frequently in teamfights), untargetability, disruption and damage reduction. He's great at peeling/protecting for his team and the vision provided by his saplings is quite useful.
The Doge
- He an extremely potent mid-game threat whose durability and sustain can make him extremely difficult to push out of lane. His laning phase can be quite safe (provided you have proper wave management) due to his sustain and how difficult it can be to dive him (between Wither, Armor Reduction, and his ultimate providing health). He can become a split-pushing menace who requires multiple enemies to properly kite or kill even as he decimates towers.