I have 3 recommendations for you on Ploymer 3D printers depending on what materials you would like to print. These are all FDM or FFF type machines.
If you are looking to print high temp polymers (PEEK, ULTEM etc.) I would suggest one of the Intamsys machines (depending on the build volume you require) https://www.intamsys.com/ This machine will also print your standard filaments PLA, TPU etc.
If you dont need to print high temp materials I would look at the Ultimaker systems, very reliable and consistent with a large range of supported materials available. Alternativly a Prusa i3 would be a good machine also.
All of the above offer single or dual extrusion machines once again depending on you needs.
Hope this helps. Happy to discuss further if you would like.
unfortunately your needs are not defined. If it is suitable for you in my opinion Pursa i3 MK3S has the best cost-value ratio. It is not too expensive and very realiable. But it all depends on your needs.
It pretty much depends on the application and material you would like to print. However, for using PLA, ABS, Flexible filaments, I second Guido's recommendation, Prusa i3 MK3 is cost effective and accurate enough for many prototyping and research purposes.
based on your question, here are the companies are known for producing 3D-print machines, Electro-Optical Systems(Germany), Arcam(Sweden), MCP Tooling Technologies(UK), and Stratasys, 3D Systems, Optomec, and Z Corporation(USA). You can find the specific 3D-printer machine that you are looking for.