what are some of best tonearms you own or experience with.

I haven't owned all that many, but the Graham Phantom III is the best tonearm I've owned.

Well Harry of VPI is describing some of the 3D printed Tonearms on straightness  issues better than me :

quoted from VPI forums :Re: Are Audio magazine rating worth anything?

by Harry » Wed Jan 20, 2021 11:26 am 

You can call VPI and they will deal with it for you or you can do what I do and warm up the headshell and just make it straight. All 3D printing, especially when it is thin like that has a memory from when it was made. I just warm it up and make it straight with my wife's hair blower, but if you would rather have a new one contact the office.  

HW

Are you kidding me?

Unfortunately not, follow the link.
it’s beyond my logic that I had to use hair driers to straighten grossly,  6,000 usd VPI Tonearms by hand.

Arms, I’ve had a few

An oldy but never surpassed: Syrinx PU-2 or PU-3.

I actually prefrred the PU2, musically better integrated across the spectrum, PU3 fiddly to set up optimally.

I ran the SME5 for some years. It benefited greatly from the Sumiko Analog Survival kit; its arm tube had a way of ’talking back’ to the cartridge. The Sumiko kit shut that up.

When I distributed the SME V, it never spoke back to me.
Damping killed the sound, analog survival kit ( yes I sold these too ) killed the arm. My view is the SME V is underrated, but the issue is it does not suit lower compliance cartridges - killed Koetsu’s etc. Sounds excellent with medium compliance vdh mc’s.

Graham Phantom on Micro Seiki 5000 - lumpy ill defined mid bass.

Kuzma 4point11 - had great results with both Kuzma CAR50 & Ven den Hul Colibri ( even with slight mismatch on compliance/eff mass ). Surpassed both Helius Omega & Moerch DP8 on same TT. High effective mass requires careful matching.

SME 3012R - musical, but ultimately coloured, imprecise through upper bass lower mid.

VPI’s - mostly garbage - engineering quality is very low as has been articulated in this thread - I mean do you think that if the posters all used a hair drier before posting on the forum they would think straight - dont think so.

Zeta - loved mine with koetsu’s and Deccas AFTER I had the shonky bearings replaced.

Alphason HR100S - matched beautifully with Garrotised Koetsu Red - nothing else though.

Tiktok - actually quite good with MM’s and medium compliance MC’s, tracked my Ikeda 9 surprisdingly well, but  each one sounds different and soft bearings easily damaged.

Ekos - blah

There are many others I’ve fettled - Sumiko MDC800, Breuer were great with specific cartridges, many others forgotten.

Arms I have kept -

Eminent Technology ET2 air bearing linear tracker ( modded ) - if you want to count the chairs in the apse of a live baroque concert in a church, this is the arm for you. Unsurpassed in transparency of soundstage.

FR64S with B60/silver wire - I use this with koetsu’s & my Ikeda Kiwame, superb grip and transparency with these low compliance MC’s.

Naim Aro - fast and fluid I use this with my medium compliance Dynavector Karat Nova 13 freshly rebuilt for me by Dynavector. The Karat Nova in the Aro surprisingly betters the Dynavector 501, which I have rebuilt to Baerwald specs, in presenting an accurate bottom end tonality. the ARO though only excels with a narrow range of cartridges.
Sounds awful with high compliance cartridges, but tracked my Ikeda 9 amazingly well despite Ikedas objections to unipivots.

Dynavector 501 - starting point on my reference Final Audio VTT1 in the 80’s - very dynamic, works surprisngly well with wide range of cartridges from high compliant Shure V15vxmr through to diffcult trackers like the Decca Golds, but ultimately I prefer the above 3.

At the end of the day, there is no best. Each arm has to be appraised in the context of what cartridges are used. The arm/cartridge synergy is so often disregarded on these forums, and yet in my view it is so vital in achieving the optimum outcome in terms of transparency, coherence, musicality and tracking proficiency.