Years of conversation fill a ton of digital pages, and we've kept all of it accessible to browse or copy over. Whether you're looking for reveal articles for older champions, or the first time that Rammus rolled into an "OK" thread, or anything in between, you can find it here. When you're finished, check out the boards to join in the latest League of Legends discussions.
Probably missing some but I think you get the point I'm making here.
Comment below rating threshold, click here to show it.
The list is huge, because a lot of champion can initiate fights. It basically comes down to your team composition and strategy.
Some initiate by locking down one guy (e.g. Maokai, Leona); some disrupt single champion/entire team positioning (e.g. Gragas, Orianna); some shut down the whole enemy team outright (e.g. Amumu, Galio).
You have hard initiators, who basically go in and will probably survive the initial onslaught of enemy attacks (e.g. Malphite, Alistar, Singed). You have soft initiators, who will need immediate protection and/or escape option after they make the first move (e.g. Morgana, Cassiopeia). Then there is a mix too. For example, Sona can play hard suicidal initiator.
Finally, you get indirect initiators like Shen (who can initiate on his own anyway) and Zilean, who can allow practically anyone to initiate by offering some form of death prevention.