bitcoin only. All other coins including ethereum are ponzi schemes.
Its innovations are the only ones that actually matter in the entire crypto space. All other cryptos are basically sticking spoilers and rims on a car and calling it an "innovation".
No, that's not an "innovation", that's just changing a few letters on a lower quality, more fragile, more defective product, making it spin faster and shinier, sprinkling it with technical gibberish and buzzwords, then marketing that as the next bitcoin. No.
Bitcoin was the innovation. Your cousin's off brand crypto? Thats just a scam.