Shalom Aleichem, What are some of the most important/ some of your favorite seforim on Halacha, Machshava, and Parsha (Besides for Shulchan Aruch for Halacha and Ramban for Parshah)

ב"ה Aleichem Shalom I think it would be correct to infer from the question that you have learning background. I don't see myself as one to rate Sefarim and furthermore choosing sefarim is a highly individualized thing dependent upon your level of learning, your preferences and your style. As a general guideline, a person needs to be familiar with some fundamental books. Let's start for example from the study of practical Halacha. I think everyone has to be familiar with the Mishna B'rura as a basis. From there, we have popular style sefarim such as Pninei Halacha, of Rav Eliezer Melamed, ( which is available in print and also downloadable for free on smartphones)though even in that series there are also many extensive footnotes to ponder upon. You have the more intensive "Piskei Teshuvot" which deals with the vast literature of the "Shutim"- Responsa and deals with many unique cases which arise in connection to everyday situations. Then there are books of Halacha which specialize in specific fields, such as Shabbat only. Take for example, Shemirat Shabbat Kehilchata, which is an extremely popular sefer. The same applies in Machshava. There are the basics such as Kuzari, Emunot ve'deot , Sefer Ha'ikarim, Iggrot Harambam, introduction of the Rambam to the Mishna and many more. From later genrations who have the Maharal and the Ramchal, not to mention contemporaries such as Rav Kook zt"l and Rav Soloveichic zt"l. There are also Chassidut books and the list goes on. For the Parsha, I think has to start from Rashi and from there are countless commentaries. So I guess, to sum up, if it possible there is a sea of Torah sefarim. To get more specialized guidance you should consult a Rabbi you are close too, who is familiar with your level and preferences. On the other hand, in order not to get lost with all the Sefarim, a person should have a daily routine of Torah learning with one sefer at least to have daily learning and progress. Happy Independence day. All the best and stay well.