Except with that absurd Bash buff, Smash is 99% no longer ideal anymore.
The strongest all-purpose melee weapon is probably the Fanatic Greatsword. It's fast enough to hit twice with Bash and can reach up to 4 piercing. Divine/Demonic/Celtic Swords are all excellent for Final Hit use. Lances are best used by Giants or when Smiting Girgashiy.
Fanatic Bash: 380~460% damage, 1 hit per second, bypasses up to 20% protection
Lance Smash: 600~828% damage, 1 hit per 3 seconds, bypasses up to 45% protection
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If nothing else, this does a great job of highlighting how fucking bad the extra Smash effects are.