League-of-legends – cap for Sion’s Enrage

[Updated for Season 3]

The game is currently in flux (season 3 has only been out for a couple days), but with the boosted ambient gold gain, it appears you only need one gp/10. I've been building Philo Stone to great success. If you expect to get some significant assist-gold (you're confident in your kill lane, or you're Soraka and have a good eye for your ultimate), you could probably stand to buy a Kage's Lucky Pick, but I much prefer to only buy the one Philo Stone and start immediately after into my build (Sightstone, Shurelya's, Aegis -> Bulwark).

Again though, this is all pretty fresh. Your mileage may vary.

[NOTE: The answer below was provided for season 2. There were significant changes implemented for Season 3, and this answer is now out of date. It is provided here for history, but should not be followed.]

It depends. The rule of thumb is two (Philo Stone and Heart of Gold), and 98.355% of the games, you'll want those. If the game is going to absolute crap, teamfights started early and your team is getting routed, you may have to skip the second and start pouring that extra money into wards and an oracle's (counter to what you'd think, oracle's is a great purchase if you're falling behind and the laning phase is over).

I'd be very suspicious of my support if they got a third gp/5. The only real time I can see that being worthwhile is if you know it'll be a late, late game, and that you'll need to be a significant contributor in teamfights for damage.

I generally max my W first for three reasons:

Harass
Buffing teammates
Stacking my passive

The reason I get it to harass, is because you can shoot your opposing lanemate through his minions, and it makes it slightly harder for him to farm with that debuff.

The buff it provides your teammates when pushing towers down is paltry at best if you max it second. Maxing it first, however, means that it will be Lv 4-5 by the time your towers are going down. Its a very good utility spell for the team!

His W makes stacking his passive extremely easy early game. If your support is doing it right, you can get 2-3 stacks on your passive with just one W! That means you're able to harass or farm at a +30% rate over your opponent BEFORE taking into account the debuff placed on him by said W.

Sure its not nearly as spammable as his Q, but you use less mana when harassing for slightly less damage, but the ability to harass through minions where he thinks he's safe from your wrath. Besides, the buff/debuff (damage too!) scales well with levels, whereas the Q only scales damage (the CDR doesn't scale at all, so why bother maxing it first?) and isn't as useful early game (in my opinion).

Hope that helps!