Another vote for the 1964 Quads. Plenty of low end for the bass, yet plenty of clarity and definition for everything else.
At just under $600.00, they aren't cheap. But they are worth saving for, or foregoing some things (hopefully, not food or rent...

) ignored to save up for them.
It's my personal preference (read that again, carefully) to roll a little bit of low end (-2 dB or so) out of my ear mix. It has to do with my hearing at 57 years old than anything else. I have trouble distinguishing pitches lower than low F on the E string and I play 5-strings with the low B. Rolling off a little low end helps that problem greatly. It's my problem, not a problem with the Quads. I'd much rather have the low end there to roll off than to have to boost the lows in another set of IEMs.
If that's a bit rich for you, or you don't want to wait the 3-4 weeks to get them made (the wait is totally worth it), I like the Westone UM30s, a generic 3-driver set of IEMs. I used a set for a week while I waited on a replacement cable for my Quads after I broke the connector. I was rather impressed with the Westones, although I was glad to get my Quads back. The Westones are just under $400. When I can, I plan to get a set of Westones as a set of spares when I can.