- Software Development Life Cycle (SDLC)
- Agile methods
- Model Based Systems Engineering (MBSE)
- General verification/validation
- Software test management
- Software test management with scripting
- Issue and change management
- Product definition from a market research angle
- Cost management
- Resource management
- Project communications
- Scope and requirements definition
- Quality management
- Configuration management
As a result, all the solutions I have looked at work for only a small portion of project management. For example, MS Project would be useless for requirements management, and DOORS would be useless for project scheduling.
Some developers stress integration of their products with other products -- preferably their own. For example, Rational (specializing in SDLC) bought DOORS and worked on integrating the two product lines. Then IBM bought Rational and expanded the integration effort to include other IBM products.
Implementing many PM software products and then tailoring them to the organization's needs can require permanent, trained resources. Integrating several products can take years, even in large organizations.
With the current state, I believe any attempt at a total PM solution will require a very large initial effort, significant support to maintain the solution, and an acceptance that some interfaces between PM processes just have to be done by hand.
Therefore, to answer the question, "What is the best software/tool for end-to-end Project Management?" you need to prioritize the areas of PM because no product addresses the end-to-end needs -- or at least, the top-to-bottom needs.