What is the most comprehensive model of executive control? Wikipedia has a nice summary of the various models of executive function, but what is the most comprehensive one? That is, the one that accounts for the most cognitive variations among subjects and can be applied to the most tasks.
Currently, the most comprehensive cognitive model of executive functions would have to be the model proposed by Miyake et al. (2000).
(It is probably best not to confuse being the most comprehensive cognitive model with being a strong explanation, because the executive functions remain one of the most poorly understood areas of cognition, but it's a very useful model.)
Miyake-Friedman Model

This individual differences study examined the separability of three often postulated executive functions—mental set shifting (“Shifting”), information updating and monitoring (“Updating”), and inhibition of prepotent responses (“Inhibition”)—and their roles in complex “frontal lobe” or “executive” tasks.

This influential model has engendered thousands of papers applying it to explain many different findings and domains. Psychometric research using confirmatory factor analysis (Duan, Wei, Wang and Shi, 2010) found support for three shifting, updating and inhibition factors, and Friedman et al. (2006) reported evidence for the factors' discriminant validity by comparing it with the Wechsler IQ scale. Practical support for the model has also come from research on ADHD, as reviewed in Wilcutt et al. (2005), and attentional problems in school settings (Friedman et al., 2007).
Finally, the NIH Toolbox Cognition Battery also includes an executive functions test informed by the Miyake and Friedman model, which recently received strong support in a review by Zelazo et al. (2013):

In the current study, we sought to assess the reliability and validity of new measures of EF and attention that are part of the NIH Toolbox CB. New versions of the DCCS and the flanker task were designed to provide assessments of two aspects of EF, cognitive flexibility (Toolbox DCCS) and inhibitory control in the context of visual selective attention (Toolbox Flanker). Together with a separate measure of working memory (see Tulsky et al., Chapter 5, this volume), these measures capture the three aspects of EF identified by Miyake et al. (2000) in their work with adults.
Overall, results reveal excellent developmental sensitivity across childhood, excellent test–retest reliability, and excellent convergent validity (except for the Toolbox Flanker, which showed adequate convergent validity among 8–15 year olds). Correlations between the new NIH Toolbox measures and corresponding convergent measures were generally quite high, although for younger children, they were higher for the DCCS than for the flanker measures.

Overall, the tripartite Miyake and Friedman model is extremely well-supported by both the literature and praxis. If a more comprehensive cognitive model of executive function exists, I am not aware of it.
References

Duan, X., Wei, S., Wang, G., &amp; Shi, J. (2010). The relationship between executive functions and intelligence on 11-to 12-year-old children. Psychological Test and Assessment Modeling, 52(4), 419-431.
Friedman, N. P., Haberstick, B. C., Willcutt, E. G., Miyake, A., Young, S. E., Corley, R. P., &amp; Hewitt, J. K. (2007). Greater attention problems during childhood predict poorer executive functioning in late adolescence. Psychological Science, 18(10), 893-900.
Miyake, A., Friedman, N. P., Emerson, M. J., Witzki, A. H., Howerter, A., &amp; Wager, T. D. (2000). The unity and diversity of executive functions and their contributions to complex “frontal lobe” tasks: A latent variable analysis. Cognitive psychology, 41(1), 49-100.
Willcutt, E. G., Doyle, A. E., Nigg, J. T., Faraone, S. V., &amp; Pennington, B. F. (2005). Validity of the executive function theory of attention-deficit/hyperactivity disorder: a meta-analytic review. Biological psychiatry, 57(11), 1336-1346.
Zelazo, P. D., Anderson, J. E., Richler, J., Wallner‐Allen, K., Beaumont, J. L., &amp; Weintraub, S. (2013). II. NIH toolbox cognition battery (CB): measuring executive function and attention. Monographs of the Society for Research in Child Development, 78(4), 16-33.