Should I go for H1-B Visa stamping on Company-A where I work or Company-B which got my H1-B transferred but I never joined Company-B?

Where you are sponsored by company A, later sponsored by company B for H-1B transfer, but never work for Company B and instead continue with company A, you are not obligated to work for company B. When you leave the US in order to have your H-1B visa stamped, you should use the form I – 797 from company A. You may wish to check with company B in the future to see whether it has already canceled your approval. Most prudent companies would have already done so if they knew that you were not going to join them. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.

Since you are not working for Company B, you should not use the I-797 from that company to renew your visa.