There are none that i really struggle without - a few that I miss, but not enough to replace them.
I pined a bit for a lovely Sandberg TT4 that I'd sold too hastily, but when it came back up for sale on here a few years ago, I didn't buy it back.
I miss my Epi Jack Casady, my PRS Se Bernie Marsden, my old 1980s Charvel Model 1B bass, but i'll live without them easily enough.
The ride was fun at the time.