Not Updated For Current Season
Kayle, The Hybrid
Kayle is everything I love in a champ, she can hold her own in a fight solo, can heal allies, has a speed boost, has a snare... The beauty of playing her as a hybrid is there's no specific way to build to negate her damage, if you stack magic resist her phys attack hurts, if you stack armour reckoning destroys you. I tend to slant more towards the magic side of things because it does mean you can chuck off a 300-400 health heal every now and then, which while it is a pretty small amount, can be enough to save a teammate from death by karthus or just plain escape.
While Kayle is an excellent champion since they buffed her (and i'm so glad very few people realise just how good or I wouldn't get away with some of the things I pull ;)), her ulti is quite frankly awful. It's worth having the one point in it to get the initial 2 second duration to really screw with champions who unload a large spike like Twitch or Ryze, but points after that only extend the duration by 0.5 of a second. It also won't protect you from slows, stuns and other nasty effects that exist to make sure you die instantly after the 2 second duration, so make it count.
Harass a LOT with reckoning, you want to make them fear to get close to the minions. Ideally you want them back out of your reckoning range while you attack the rearmost minion, so that they're out of range to gain experience. Be careful you don't get snared and ganked when you're that far forwards, however, as you don't have much to escape with.
You will find yourself slightly mana-starved if you harass too much until you get the mana item sheen requires, that's what clarity's for. If you find yourself needing to recall try to sync it with either your teleport being ready to get right back, or when you have enough gold to buy something shiny so that you come back stronger than before each time. Ideally you want both but teleport's cooldown is extremely long so it might not always work out.
Don't be selfish with your support abilities, if you can put your ulti on an ally they're unloading on not only will the enemy champions waste their most powerful abilities to try and get the kill before they even realise, but your ally might manage to get out of there. In addition to this, melee champs all attacking the same person make a lovely target for righteous fury ;)
Your heal should be used on OTHER PEOPLE when your team is close to catching a runner. Chances are if they're ahead of you you won't be able to catch up in time even with the boost, and healing someone else can ensure you at least get an assist due to the healing, or allow someone like xin zhao to get close enough to slow them down and prevent their escape for you to drop the reckoning bomb.
I did have some more tips but I spent so long typing this wall of text that it logged me out and lost some of it, ah well, it was getting a bit too long anyway.
Note 1: I've updated the items in this build as I originally wrote this pre-manamune patch >.< So yeah, this is the newest version, I like having both the staff and manamune (if it lasts long enough) because while the mana bonus caps out (after a long time) the non-unique passives work well together with kayle :) I've never actually reached the full item build, even in matches where i've been fed, but meh
Note 2: I have dodge runes in my yellows, simply because i'd personally rather have the dodge chance than more offensive stats, considering you get a negligible amount out of yellow rune slots and dodging an attack is sometimes enough to win a fight, especially against someone like gangplank. That said, they're not vital to the build, they're just my personal preference, if you'd rather have regen or health or moar damage that's up to you ;)