Although it is an individual perspective to choose out of different options, still I would list out my preferences in favor of ISTQB due to its distinguished approach & following factors
1) ISTQB is internationally recognized collegial, knowledge sharing organization.
2) ISTQB happens to be the first choice of multi-national companies who prefer an internationally recognized qualification.
3) ISTQB certification means – its holder has access to the essence of wisdom compiled by several stalwarts in testing like consultants, trainers, practitioners & academicians.
4) ISTQB certification recognized in over 46 countries having their own local / National Boards.
5)) For appearing in ISTQB exams the aspirant need not have any formal training.
6)) There is no need of a re-certification
7)) Focus of ISTQB lies more on practical and real-world activities related to testing
8) Syllabus of ISTQB Advanced level is built on top of ISTQB Foundation level that is adopted by ISEB as well
9) The ISTQB syllabus clearly describes the objectives of learning, so that the aspirants have great clarity on the each & aspect of the exam.
10) Multiple choice exam questions – a comfortable option for non-English speaking aspirants.
11) ISTQB provides a comprehensive career path with varied levels of certification
12) ISTQB helps in promoting the software testing profession.
13) Comfortable route to ISTQB advanced level certifications like Test Analysis, Technical Test Analysis or Test Management compared to ISEB route.
14) New ISEB Practitioner Certificates does not enjoy equivalency with ISTQB Advanced Level Testing Professional certificate. Hence ISEB Practitioner Certificate holders are unable to go in for expert level in ISTQB but instead requires a pre-requisite of ISTQB Advanced level.
For a quick understanding of different certifications - read the article titled
How to be one up on the rest of the testing community? How to chose the best certification?
Highlights of few of the ISTQB Certification:
ISTQB Foundation Level Certification (Entry-level certification)