I have heard many derogatory things about Zhuge Liang before and thought I'd refute some of those points...
1. Zhuge Liang was a power hungry politician.
Fact: Zhuge Liang's only benefit from his career as Shu prime minister were the plots of land he was rewarded with by the Lius.
Quote from an earlier post of mine last year
Under Zhuge's administration, Shu, which was weak, became a rich kingdom. He did not amass wealth for himself. He told Liu Shan: "I have 800 mulberry trees and 15 qing of farmland. These are more than sufficient to feed and clothe my children. Other than these, I have no other property." (1 qing = 0.6667 ha)
Excerpt of Zhuge's SGZ bio
Earlier, Zhuge Liang had memorialised to the Latter Lord: "This subject has eight hundred mulberry trees and fifteen hectares of land, more than enough to clothe and feed my relatives. When this subject is out on assignment, my clothing and food are provided for by the bureaucracy. This is the sole benefit of my post; there are no other sources of income. On the day this subject dies, in accountability to Your Majesty's kindness, my family shall have no extra yarn nor property than is needed." And after his death, it was as he had said.
The political power of Shu was not completely in the hands of Zhuge Liang. Men like Fei Wei, Guo Youzhi and Dong Yun were recommended by Zhuge to Liu Shan to jointly advise Liu on court matters and Xiang Chong was recommended to manage millitary affairs.
Also, the reason for Zhuge Liang wielding near complete power of Shu was attributed to the fact that Liu Shan was still young and inexperienced when Liu Bei died.
2. Zhuge Liang was stubborn and blamed his failures on lesser officers.
Fact: Zhuge Liang accepted all responsibility for Ma Su's loss at Jieting, his failure at capturing Chen Cang. He even went to the extent to memorialise for a demotion due to his carelessness, but was reinstated with the excuse that the siege of Chen Cang was not a complete failure, considering that Wang Shuang, a valiant Wei officer was slain.
3. Zhuge Liang was not the genius he was purported to be in SGYY.
Fact: The invention of the wooden oxen for faster transport of provisions and the invention of the mechanised crossbow were indeed credited to Zhuge.
In his SGZ bio, Sima Yi checked Zhuge's barracks and encampments after the latter's death and remarked "Indeed he was a genius of the Empire!".
4. Zhuge Liang had was an untalented strategist.
That isn't completely true, certainly Zhuge's political skill can be compared to men like Guan Zhong or even Xiao He. Yet his failings at invading Chang An were often associated to the superiority of the Wei officers guarding the western borders, the lack of talented officers of the calibre of men like Han Xin, Wu Zixu and Wang Jian in Shu's ranks, and sometimes because of sudden changes in weather.
The war manuals compiled by Zhuge Liang held some merit in grasping the concepts of strategic planning and are still studied by scholars to this day.