I've done this multiple times before but here we go (USA versions of each)
Playstation Network
- Videos for download (rental/purchase) some exclusive videos
- Free online Multiplayer
- Netflix
- Ad Hoc Party (play PSP games online)
- Life With Playstation (I don't know exactly what it does. Cures cancer?)
- demos for most games (sometimes it takes a while for demos to come out, though)
- keep track of friends that are online, what they're playing, when they last logged in
- video chat (with PS Eye camera)
- Qore (Virtual Newsletter)
- Player review system
- send and recieve messages and pictures
- built in porn browser
- Playstation Home (virtual social network)
- Playstation Store with a library of great downloadable games
- PSN Plus (price varies depending on how long you subscribe to) offers special discounts and privileges
Xbox Live
- videos for download (rental /purchase) some exclusive programs like "The Guild". Purchases can be redownloaded multiple times
- Online costs up to $60 a year
- Netflix (on 360, you can watch a movie with friends online)
- demos for all Xbox Live games
- Video Chat (with Live Vision camera)
- Send and receive messages (including voice messages) and pictures
- Independent games (often cost $1)
- Game Room (for classic arcade game fans)
- dedicated Last.FM, Facebook, Twitter "apps" (PSN has a browser but performance varies with certain sites)
- Windows Live Messenger
- Inside Xbox (news and information)
- Complaint system (also preference system if there are certain people you prefer playing with)
- Compare games/Achievements (Leaderboards for most games--all XBLA games)
- Dedicated schedules for playing certain games or groups (for example, "Game w/ Fame", "Family Night", "Ladies Night")
- Customizeable Avatar, gamer pic, and profile information (motto, biography, "gamer zone", etc)
- Cross game chat (for talking to anybody regardless of what they're playing)
Misc.: Both consoles can connect to portable devices like an iPod, Smart Phone, or PSP (Even the 360) and view content from the device. 360's received messages disappear after 30 days and sent messages are not stored. 360 offers customizable playlists for all games. 360 allows for multiple accounts to be logged in at the same time as opposed to only a few games on PS3 offering this feature. PS3 has dedicated servers (for many games) 360 has P2P server for (most games). PS3 supports Blue Tooth (sold seperately). 360 consoles come with free wired headsets. PSN games can be downloaded on mulitple consoles. Xbox Live profiles can be accessed from any Live enabled 360. Movies/TV shows purchased on PSN can be downloaded only once. If they are deleted, they are gone forever.
Nintendo Wii
- Free online
- News Channel
- Weather Channel
- Nintendo Channel (virtual fan network offers news, trailers, recommendations, records of games played, and downloadable demos for DS games)
- Check Mii Out: I can't explain it.
- Mii Plaza (Prison for your created "Mii" character)
- Everybody Votes Channel (asks a question and grades you based on what the majority chose)
- Photo Channel --Stores photos to edit/share with other Wii users
- Friend Codes: A complicated but safe way to play online with others without fear of predators
- Message boards for tracking what you've done on your Wii that day as well as sending and recieving messages
- Built in porn browser
- Netflix
- Wii Ware and Virtual Console for downloading classic games as well as new experiences
- Gift system for sending/receiveing games among friends
Misc. Wii is the only console that currently offers a "Gifting System". Some games do not require a friend code. Wii Browser is not compatable with many web sites.
Based on which console you own (I believe you are a PS3 gamer) and how important online is to you, each console has its own strengths and weaknesses as far as online is concerned. I've left out several other details and upcoming features but this should give you a good idea what each service has to offer.