The Whole Is Greater Than The Sum Of Its Parts
I love "Fidels" and have been coming here for over 20 years. I really liked their food, but I don't think it's "transcendently great" per se. To me, the allure of Fidels is in the overall experience: the unusual, house-like structure of the place (and its "Rosarito" decor), the very good (but not great) food, and the off-beat location in Solana Beach. All combine to make a great, unique experience which is somehow more than the individual parts. I'll elaborate:
When I was a teenager in Del Mar in the 1980s, this was sort of our version of Old Towne. Back then the area it is located in, Eden Gardens, was also a little dangerous. So that added to the allure in a way. It was sort of weird that this very popular, family-friendly mexican restaurant was located in this little corner of Solana Beach that was off the beaten path and that left you a little worried for your car as you went inside.
Inside, "Fidels" is surprisingly big, with multiple levels and a nice outside courtyard area, too. Another reviewer said its decor is reminiscent of Roasrito, and I agree. Though I would say it's a mix of that and the old "Casa Di Bandini" in Old Towne.
It's a credit to the food at Fidels and its ambiance that it remains crowded to this day, especially at peak times like weekend nights and during racing season. I just avoid it entirely during peak times now, though, because the wait can be interminable if you go then without any reservations.
Another problem with waiting at peak times is that there are tons of other people waiting, all crowding the bar and making it hard to even get a drink while you wait. But there's an easy solution to that: just don't go at peak times.