≤ ≥ ≠ × — – “ ” ’ ° … ¹ ² ³ ™ • ♣ ♢ ♡ ♠
If you work in languages other than English but have a standard English keyboard layout, a compose key is handy for typing accents and non-English letters/ligatures too.
[0] The AltGrDead variant just means that the regular dead keys on the US Intl are flipped; e.g. ' is now no longer dead per default: I have to hit altgr+' to make it dead (i.e. an acute accent (´)).