EnergyPlus is the official building simulation software of the US Dept of Energy. It is available free to the whole world. It is actually a simulation engine.
The most compatible analysis tool with BIM and especially Revit is Green Building Good luck.
I think the selection or use of an energy simulation software should be tailored to the intended purpose or result needed. I would ascribe 'best' to any. Similar way to BIM software.
That depends on what you want to study. Trnsys(including Trnbuild) started from solar equipment system. So It is good software if you want to input the building equipment system more correctly. Trnsys reinfored building part quite well and it's updating building part annually. But it's expensive.
EnergyPlus is freeware and it started from building energy simulation. It's reinforcing equipement parts. It use DOE-2 Engeen. Many archetectural engeener use energy plus instead of trnsys.
And if you want to co-simulation other programs(i.e. BCVTB, Matlab, Fluent), it doesn't matter what you use EnergyPlus or Trnsys.
Agree with previous comments, horses for courses. For high-performance buildings, PHPP could be a contender, as it has a large number of POEs attesting to the accuracy of its predictions for energy consumption. I am not aware of any other software with an appreciable number of real world testing to determine accuracy. But PHPP, as all other software, has limitations, so it depends on your research question. Energy+ is good, but comes with another set of limitations. What are you after?
Accuracy in a simulation software depends on, among other aspects the weather files, the capability of simulation engine ie. 8760 hours or less, and the factors that need to be simulated (for eg. some software provide better output for solar geometry while others are better for heat gain and heating/cooling load calculations. For a list of simulaiton software that the Bureau of Energy Efficiency in India recommends, see the link to ECBC 2017 (appendix E).
Depends on the objective of your simulation. For example, if you want to know if the Passive House indicators are reached, I would say that PHPP would be the better software. If you want to analyze the building performance developing an optimization analysis the best software is Energy Plus. For Lighting analysis, Radiance would be a good choice.
The question as stated is very generic. That's leading to a broad range of somewhat vague responses. Are you studying residential or commercial buildings? Are they new (in design) or existing (calibrated M&V)? No software is perfect. The old adage "garbage in, garbage out" holds true for even the best software. When attempting to model and design a net zero facility, you need accurate occupancy data and plug loads. Others have noted that some software can also estimate the renewable production, but you need to make sure the building simulation is representative of how it will be used--otherwise you might as well consider an asset-based score.
For ease of use I would suggest eQUEST (free) or Trane TRACE.
IES-VE is a good middle of the road option, but has a significant cost. It's based on ESP-r
EnergyPlus is an engine that you can edit through the IDF editor (modest free user interface) or there are better user interfaces such as Open Studio (free) or DesignBuilder.
TRNSYS and Modelica are more sophisticated models.
As was previously stated, it really depends on what you want to achieve with the model that should dictate the tool you're using.
Most tools have email list-servs and there's UnmetHours.com that is a good user forum.
Last note; as a manager of 8 energy modelers and being one myself, don't attempt to model something complex without training. The tools are generally sophisticated (some more than others) and have lots of ways to make mistakes. I have seen lots of poor quality models generated over the years by new users because they missed some critical component buried in the tool.
Would agree to Mr. Betz on idea that the tool should be picked by the level usage from easy to hard. It is important to understand what kind of aspects you are focusing to explore. My own experience and opinion about tools suitability and accuracy:
1.PHPP - Has very detailed inputs on building envelope (window frame area in high accuracy, linear and pointial thermal bridges etc.) which may be dificult to input in other tools. There is ways to input geometry by hand and from sketchup model. But it is important to mention that it is steady state calculation based on EN 13790 with know-how from Passive House Institute. The specific here is that German engineers prefers to be "at safe side" and that some times creates difficulties when innovative mechanical systems is used in assesment. Good thing is that last version has Quality assurance functionality already built in.
2. IES VE - with this tool there is possible to simulate the building and mechanical systems in variuos levels of detailness. Main diference from other tools (Energy+ and eQuest) that it is "one stop shop" for Life cycle impact analysis, CFD, Artificial and naturali light simulations. Great reusability for model geometry and coupling between diferent types of analysis tools.
3.TRNSYS - nothing is imposible with this tool. No boundaries for configurations and detailness of simulation model. This tool unbounded flexibility and posibilities to connect to external tools like Fluent, Matlab, ESP-r and ESS. But that brings the uncertainty and lots of risk how to combine accurate model from individual components.