A two year path to an RN such as a diploma or an associates degree is faster and much more affordable. Typically they can be completed in 2-3 years.
A BSN will typically take 4 years to complete. You will have alot more gen ed requirements, which will give you a well rounded education. Be prepared to invest more financially than the first two options.
The desirability of the different options can really depend on what part of the country you are in. Where are started out as a new grad there are alot of ADN and diploma RN new grads, none of which had trouble getting hired by the hospitals. However, some parts of the country have found it isn't that easy.
this is one of the most contentious issues in nursing: the level of education needed for a profession. as many of the an'rs know, i come down squarely on the side of a bs in nursing or bsn as entry-level educational preparation. when i had smaller kids and they asked me a question, i always asked them, "do you want the short answer or the long one?" since i can count on the fingers of one hand the number of times they ever said, "short" and still have enough left over for the boy scout salute, here it is again.
(disclaimer: have worked as a staff nurse, inservice/staff development, instructor, nclex prep course instructor, case manager in multiple settings, and other stuff too numerous to mention. in short, been around, seen that, done that.)
what's a profession? is nursing a profession? what's the basic educational prep for people you think of as professionals? would you want your chemistry research done by someone with an associate degree? your child taught high school math or english? your income tax advising? sure, there are good people with lower level education who succeed in life, but don't let that "we all have the same license and sit for the same exam" fool you. better education makes you better at what you do. there are any number of people who can give you examples of bsns or mns who don't know how to take a rectal temp (why does everyone focus on that and bedpans when they think of nursing, anyway?) and marvelous crusty old lpns who saved the resident's butt one dark and stormy night, but for every single one of those i will see your anecdote and raise you half a dozen godawful errors made by nurses who didn't take the coursework and didn't get exposed to the idea of autonomy in school.
time: the bachelor's degree takes four years. the associate's degree (as or asn) takes ... three and a half, once you count all the prerequisites you're going to have to take before they admit you into the nursing program. and those who say you can work on your bsn while you are working as an rn with an as don't tell you (and maybe don't know, to be charitable) that many of your course hours from the as program are not transferrable, so it won't just be a matter of a semester or two or three. and working as a nurse is hard, almost as hard as nursing school ... think you'll have the mental, physical, social, and financial energy for more education at the same time? oh, and in most jurisdictions you can't sit for the lpn exam and work as one while partway thru a as or bsn program anymore, either.
job opportunities: although the old a-nurse-is-a-nurse-is-a-nurse attitude is fortunately fading away, at entry level for new grads, about the same, and i realize that people who are just starting out have a very incomplete idea of what it means to be a nurse. however, look around the place and see who's working. are you planning to be older some day? do you see older nurses working in those entry-level staff or charge positions? if not, where did they all go? why do you care? well, suppose you work on a general medical floor and get entranced by cardiac rehabilitation after following a patient who did it. a job comes up in the department, hooray! oops, bsn only. or you find your heart drawn to helping underserved women in a public health clinic for high-risk pregnancy. sorry, bsn only in public health. after five or six years as a staff nurse you have become a resource to new hires and your peers and you realize you have a gift for teaching. you see that a position in staff development has come open, and you are first in line at hr to apply. you got it.... bsn is the minimum. school nursing? bsn. hurt your back and want to go for a job in case management? bsn. you discover you have a gift for asking, "why do we do it this way?" and are amazed to find you want to look into jobs in management or nursing research.....bsn minimum. you are starting to get the picture now. also, many, many practice settings give you a differential for bsn. no, i know, not all, but hey. one more factor.
growth: the questions in the licensure exams (nclex) are developed from errors made in the first year of practice by new grads, and regardless of pass rates from different level programs, anyone in practice can confirm the research: in the first year of work all new grads perform at about the same level as they get their feet under them and get used to the idea of working as an rn. but after that year, the bsns pull ahead in ways that are related to their higher level of education. why? because what we call in the ed biz "psychomotor skills," the things you do with your hands, can be done by anyone with enough practice. hell, we teach lay people how to do peritoneal dialysis at home or suction tracheostomies. but the understanding of why some things are as they are is something you get in better education: more science, more sociology, more psychology, more history, a basic statistics class, exposure to more clinical settings (i doubt if you'll get a full semester in peds, psych, ob, or any public health at all in any as program) give you the insight to ask better questions and make better decisions.
well, i hear a lot about the challenges of getting into and staying in nursing school. but if you really want to be a nurse, don't you want to find yourself in the camp of folks who are grateful they learned more, rather than the ones who find they had to for advancement or competence and wish they'd done it in the first place? my answer is clear.