Timelines suck; I never enjoy looking at fan-made timelines. Anyway, here's a fan-made timeline.
Guidelines prevent me giving myself too much license (the main reason I tend to dislike others' timelines). Mainline console releases are set in stone, order of release. Portable games can be rearranged according to what makes most sense for the established timeline of mainline games (that they often draw from in some limited way), and spinoff games (far enough from core series gameplay) are completely up for grabs, or may be omitted where they are devoid of story significance (catch me scrounging for lore significance in Sonic's Schoolhouse).
Of course, what is mainline is itself arguable; I usually go off what I perceive as common consensus; if I have any contentious picks I'll try to justify them.