I don't know of any comparison out there. Not only is suspension feel subjective to the individual, but there are a large number of factors that can affect it (vehicle sprung and unsprung weight, accessories, spring rates, suspension setups, wheels/tire types, tire pressures, adjustments for adjustable valving, etc.). I would try to figure out your needs, wants and budget and go from there.
Some basic guidelines (these are guidelines, not the rule in every situation for every product):
1) twin tube vs. monotube - twin tubes are less expensive and tend to last significantly longer (two reasons why they are used in almost all OEM vehicle builds), but are generally not rebuildable. They do not have adjustable valving options, but are typically sold with different "feel" options for different weights of vehicles. Twin tubes also are less likely to have height adjustment options, and if they are adjustable there are only a few pre-set choices. They are less susceptible to damage from rocks and debris. Monotubes have a larger internal diameter and therefore typically more oil volume, which allows for better thermal efficiency. But they typically fail sooner due to more complexity than the twin tubes and typically need to be rebuilt about every 40k-50k miles. Not an overly expensive or difficult process, but it has to be done off the vehicle, which means some vehicle downtime when that occurs. If you go this route, look for shocks that are completely rebuildable - you don't want a throw-away monotube shock. Monotubes are typically also fully adjustable for height by adjusting spring preload.
2) remote reservoirs - these add oil volume, which promotes cooling (or less heating and quicker heat dissipation) of the oil. These are nice to have with a monotube setup but really only necessary if you are running washboard roads regularly or doing desert racing. Otherwise, they won't perform any better than the same shock without the reservoir.
3) Adjustable valving - when done correctly, this can work wonders but is not usually a cheap option. This is especially good if you spend most time on-road and only want to soften up the ride for occasional weekends off-road. If you want to go this route, look for 2- or 3-way adjustments, because you are going to pay for this option you will want to adjust differently for at least compression and rebound. Make sure you know how to make adjustments, and that if someone else installs the shocks for you that they give you any necessary adjustment tools to keep with you. Popular brands that have this option include Dobinsons AMR, ARB BP-51, Radflo and King. Some have non-reservoir adjustment options, but most only have them with remote reservoirs.
4) brands - If you are going twin tube, the Australian brands typically do well - OME (ARB Old Man Emu), Dobinsons Nitrogas, FCP (Ironman Foam Cell Pro), and Tough Dog are mentioned a lot. People who offroad in Australia drive washboard roads for long distances, so the stuff used out there has to hold up to significant abuse. For monotube, you again have some very good Australian options such as Dobinsons Monotube Remote Reservoir (MRR), Dobinsons Adjustable Monotube Remote Reservoir (MRA), and ARB BP-51s. ARB is more expensive than Dobinsons, but they make very good products. There are also some good (but expensive) American brands such as King and Radflo, which make both off-the-shelf and custom options with and without reservoirs and compression/rebound adjustment knobs. Below all of these price-wise are brands like Icon, Toytec and Fox, all of which make decent products, although with less customization options.
You will find cheerleaders and haters of almost all brands and products online. Again, much of this is subjective. The only brand I would personally not recommend at all based on what I have seen would be Bilstein, especially if you plan on doing anything offroad. I have Dobinsons MRRs on my GX and ARB BP-51s on my wife's LC 200. I love both setups for different reasons, and am happy with both choices. I am sure whichever way you go you will likely be happy with the result.
