In the first category are the ping ICMPs (echo, timestamp, address mask, router solicitation, information request/reply). Of these, only the first is widely used, and presumably the victim can get by with little difficulty if replies to all of these are filtered out. (We note, though, that smurf attacks, in which the attacker sends ICMP echo requests to subnet broadcast addresses, are essentially a form of reflector DDOS attack.)
In the second category (unreachable, source quench, redirect, time exceeded, parameter problem), the most significant for the victim will be the unreachables, which include host unreachable (useful for tearing down state in some circumstance) and need fragmentation (necessary for PMTU discovery), and time exceeded (needed to run traceroute). It appears plausible that the victim would be willing to forgo these as a means to suppress a flooding attack.
Summary: reflectors generating ICMP messages can likely be filtered out.