1) As good as it gets 2) As good as possible 3) Best 4) Best possible 5) Ideal 6) Like the best-case scenario 7) Most desirable 8) Most favorable 9) Most satisfactory 10) Optimum 1) Best 2) Ideal 3) Optimum 4) Peak 
For a mathematical program in standard form, x* in X (the domain) is an optimal solution if it is a maximum (or a minimum): x* is feasible; f(x*) >= f(x) for all feasible x (maximum value). Some authors refer to an optimal solution when they mean a local optimum; others mean a member of the optimality region (which are global optima). In eithe...
the best; the most favourable.
Best, by whatever criterion decisions are being made; thus yielding the highest level of utility, profit, economic welfare, or whatever objective is being pursued.
The best, the most favourable. ... (18 Nov 1997) ... 
optimum (def. 3).