Cartridge reccomdations?

What is your table and setup? More context yields better results. 

Your path sounds like mine. I would do a search on the forum for the Audio Technical ART-9. Those who own it (myself included) swear by it. I don't think I ever want another cartridge, even though I've owned cartridges that cost twice the price. 

@masterplan it’s very personal and system dependant when you are asking for a cartridge recommendations, i don’t think the genre of music play any imporant role for the cartridge to reproduce what’s on the record. The most important is you and your personal preferences in sound. No one will tell you what is the best cartridge. No one can read what is the best cartridge based on reviews, only trying different types (MM, MI, MF or MC) in our own system is the answer. It’s a great experience and going this way you can discover that "your best cartridge" is not the most expensive cartridge, it will surprise you. It can be a cartridge made 30-40 years ago. 

SHURE Ultra 500 sounds good everywhere, quote from David (dlaloum).
I couldn´t agree more, after nearly thirty years´ experience. Still reigns.

Masterplan - If you are happy with the sound of the Shelter 501 III - why not have Soundsmith retip it !

You could have it upgraded to the more advanced stylus profiles like the Shibata, Contact Line or O.C. Contact Line.

You’ll get more details than the elliptical profile provides while maintaining the current;"tone" of the Shelter.

You will need a very accurate protractor to setup the cartridge, like the Mint Tractor, but the investment is well worth it

Drawback - It can take about 6 weeks, but well worth the wait

I have a Denon DL103 and purchased the same cartridge from Soundsmith with the O.C. Contour Line stylus and the ruby cantilever for around $650 - the improvement was nothing short of amazing.

I’m now thinking of sending the old DL 103 cartridge for some of the same treatment to have as a spare (in case of accidents) Maybe I’ll try the Shibata profile with a boron cantilever, which I think might be a little more forgiving in setting up

Regards - Steve

Masterplan, I suspect that you would get far more bang for the buck by improving record cleaning first. Going from VPI 16.5 record cleaning to ultrasound was a bigger difference, for me, than going from high end MM to higher end Koetsu.

The added advantage of record cleaning is that you are likely to increase stylus life, because the grunge in the record groove tends to contain diamond dust. Or so I have read. YMMV