Some useful LoL websites that EVERYONE should know about

** ..: Will try to keep this as updated as I can. Please offer suggestions in comments :.. **

Personal Stats (Summoner Information)

Quickfind - Gives you all the quick information you want to know about your summoner. When it was created, how much IP you have, along with a bunch of other cool information in a great layout.

LoL Summoners - You remember how Riot took down the ladders? Well these guys put it back up! It may not always be up-to-date, but you can scroll between pages to find what percentile you'd be in when it updates.

LoL Team - Ever wonder if you should be scared of that enemy Shaco? Well pull up this site and type in your name and you can see how many games everyone's played of that character, their k/d/a, their current tier (gold IV or such), and more.

LoL Nexus - Similar to LoL Team, but also shows you who is duo queue'd. It's currently disabled, but you can see a screenshot here.

Pro Builds - This is a really cool site where you can see what builds the pros are using right now. You get to see their item order, skill order, final build, gold, team, runes, masteries, and even a picture of the pro! All this in a nice-looking site that is super polished.

Spectate Us - Type in a summoner name and select a region. If that person is playing a match right now, you can click a button to spectate them with your League client.

LolKing - LolKing has been the place to go for stats for a long time, and it still is. However, there are new and better sites emerging that replicate some of LolKing's features and even have more. LolKing also has some okay guides and very cool graphs and visualizations.

Elophant - Elophant recently got a full makeover. They used to be a pay-only service that all the pros used, but now to compete with Lolking they turned to a ad-based revenue model while keeping their site free to all visitors. The advantage they have over Lolking is that Elophant shows win percentages on champions for season 3.

Elobuff - Powerful statistics. This is a pay-site as opposed to LolKing and Elophant.

LoL Counter - Helps choose Champion Counter(s).

League of Stats - Simple, easy to use site to get Summon Stats.

Champion Select - Another site to help with counter-picking

News/Pro Scene

Lolplay (League Vods) - Missed the LCS last weekend? No problem, just go to Lolplay and look up the last week. You can start watching at the picks/bans, game start, first blood, or whenever you want. They also have tournaments that aren't LCS.

Riot Esports - They have a great site with a lot of information. They have articles on past games, predictions, stats, interviews, you name it. If you love professional esports, this is the place to go.

Surrender at 20 - Do you remember MMO Champion from WoW? This is basically the same thing. News aggregator, red post tracker, articles, and more.

Reign of Gaming - Pretty similar to SurrenderAt20. They also aggregate news, have a red tracker. However, they also have awesome in-depth mathcrafting articles and multiple tier lists, including solo, competitive, jungle, threes, and dominion.

In2LoL - This looks like a news site that's more focused on the Pro scene. They also aggregate Vods and Livestreams. There's a calendar on the right counting down to the next games too, neat!

LoL Portal - Another news site, keeps a ladder of the top teams on the right, which is neat.

News of Legends - Pretty self-explanatory.

Nerf Plz - Everything from Humor to theorycrafting.

GameReplays - News, Guides and Video all on one site!

Guides and League Information

Solomid - My favorite place to go for guides. Their guides seem to be more detailed that Lolpro and cleaner in general. My only complaint is that they play a 30 second video ad at the top of the page. However, this is easily remedied with Adblock.

LolPro - Where TSM Snapdragon has solomid.net, Curse has lolpro.com. They have some good guides, although they usually have less information than solomid counterparts.

Mobafire - A highly controversial guide site. It's a great resource for newer players, but the guide quality has fallen dramatically since its launch. I find other guide sites much more useful.

League Wikia - A wiki specifically made for League of Legends. This is the one I use.

Leagueapedia - Another wiki option. They specialize in documenting the pro scene.

Is LoL up? - Tells you if the servers are up.

TeamLiquid - Probably the most reputable e-sports community website. Will be well-known to any and all RTS players.

Other Stuff

Teams of Legends - This site helps you find members for your team, of teams for you to join. You can also search for a scrim to play in. All in all, looks like a well-polished site.

LoL Patch - All patch history. Ever.

LolSkinViewer - For viewing skins before you buy them

Extensions & Addons

Chrome
LoL Stream Browser
TeamLiquid Streams
LoL Forum Extension

Firefox
Stream Notification
TeamLiquid Streams