Looking to take a trip here in 2017 either March 27-April 7 or December 26-Jan 5 in Tokyo. I've never been to Japan before and wanted to explore:

Food/SAKE!
Nightlife
Cultural landmarks
Anything else that might be cool.

I was debating the best time for all of that and taking into account which time would be more expensive. Any advice would be helpful. Thanks!

Dec 31 - Jan 4 will be New Year holiday period, so some things may be closed or schedules altered. Late March, early April you're likely to see blooming cherry blossom trees, which is a big thing in Japan. Schools are on spring break at end of March, but will start up again on April 1 or 3 next year. So, lots of kids/families potentially at beginning for your planned time. I'd lean toward the spring one, as it's a more normal time as compared to New Year holiday.

Spring is normally better, but it's going to be crowded and possibly a bit more expensive..... but both periods are nice (Jan tends to be a bit cold but normally dry and sunny).

Having been to Tokyo both in late December and mid to late March, I'd say go in late October or early November

Echoing both nishimark and RTW1...

Late March/early April will likely be in the prime hanami time. Everything will be more crowded than usual--especially on the weekends (hotels, trains, parks, etc)--and thus, more expensive. There will be crowds and street vendors everywhere that has cherry trees. This may or may not enhance your experience. It will be a bit atypical. The weather will likely be pleasant--highs ranging from 50-60 F. The Japanese school year ends at the end of March and begins again in early April--adds a bit to the families out and about.

I was in Tokyo last week. The blossoms were just starting to come out on some of the trees. On Saturday, the canal in Nakameguro was lined with street vendors and relatively heavy crowds despite only a few trees having a few blossoms. Shinjuku Central Park on Tuesday afternoon had a fair number of groups of people enjoying themselves in the grassy areas (think picnics with booze ) despite very few blossoms out--several pop-up vendors were there, including someone doing American BBQ (smelled pretty good; didn't try it).

Late December weather will be colder. Not sure where you live--compared to say, Wisconsin or Minnesota in December, it isn't really cold at all. But it won't be as much fun visiting a temple where you need to remove your shoes before entering. There weren't a lot of tourists (but that was <cough> 20 years ago). The big concern would be the New Year holiday schedules--most of which I would expect to be posted online.

Late October/early November benefits from decent weather--still getting into the 70s in Tokyo--and a relative lack of tourists, everything else being the same. (Parts of the country will have people going to view the fall colors on the trees, but not so much in Tokyo in my experience.)

Make no mistake, during the peak of hanami in spring can be amazing (although timing it right is not guaranteed). Excusing the poorly scanned images (these were actually 35mm film, not digital), the following photos were from the Imperial Palace in Tokyo and Kiyomizudera in Kyoto. The palace crowds were as impressive as the blossoms. In Kyoto, the blossom petals were like confetti in the wind.

December is cold, at least to me.

Early to mid-November in Tokyo should be prime koyo (fall color) season. In Kyoto, koyo is as beautiful as the cherry blossom season. In Tokyo, you have to look a little harder but it can still be quite striking.

Either one's fine. Nov-Apr is probably the best time to visit Tokyo weather-wise. Early-summer starts to get hot with more rain, July~Sept is very muggy, you can get typhoons from late summer through Oct.

You can expect the most sun, driest weather, and clearest sky in winter. Winter in Tokyo is not that bad... certainly far easier to bear than summer time. But as others have said, the cherry blossom in Mar~Apr will be a nice thing, plus it should be warmer.

I'd extend that to Oct to May. May is very nice weather and not as busy as other times, as Golden Week holiday has finished and many are well involved in school and work life. Rainy season will likely start in June. However, it's not rainy all the time and June can also be a great time for travel in Japan. Oct is a very busy time for Japanese families (school activities, popular wedding season), but is also great weather, as the heat of the summer has passed.

Pretty much every time of year has its pros and cons and it mostly really depends on your own personal likes & dislikes when it comes to weather and atmosphere. My personal choice would be to go in spring, because there's a bit more energy in the city and the weather's nicer. More people out, everyone seems a bit happier, feels like more is going on.

Of course some people like winter. I am not a fan of being cold myself and I also don't really like how any city feels when people are trying to avoid being outside... it just feels "dead", and Tokyo is no exception to that. Obviously the new year would be pretty busy in certain ways and in certain areas but just walking around the city on something like December 28th is going to feel as relatively quiet as any other winter day. Again, it depends on what you're used to and what your benchmark is, but to me Tokyo just doesn't have the same energy in winter as it does in spring or summer.

I have gone in summer more often than any other season and it's true that in some ways summer there is almost unbearable. I've changed clothes three times in a day there in summer. But I'd still prefer summer to winter. Spring or fall are probably the best times, though. Late March/April or October/early November are probably my favorite months to visit.

Crowded is an understatement. Especially if OP wants to go to Kyoto. If so, I'd say gong show at this time.

Would definitely recommend April - just took this picture at the end of my run just outside my place in Tokyo - sorry it's not the best quality and it's raining but you get the point - it's a beautiful time to be in Tokyo with the Sakura blossoms - and although it's a bit crowded it's worth it!

I just came back from Japan. The cherry blossoms had stopped blooming due to a cold front and only maybe 10% of the trees had bloomed during our stay. But obviously I had no way of predicting that when I booked everything - and everything was booked at a premium. Hotel prices were about 25-100% more, with many hotels being sold out or requiring crazy minimums. Also, it was very difficult booking restaurants, and all the tourist areas (castles and temples) were very crowded.

Not sure if you have kids, but don't even attempt to go to Tokyo Disney over spring break. 250 minute waits for rides (yes, over 4 hours!). We stayed at the Disney hotel, got early hotel passes, and arrived at the gate half an hour BEFORE park opening and it still took us over an hour to get in! Would you wait 2 hours for a turkey leg or popcorn? Apparently Japanese people will! There were lines everywhere! I didn't know if people were lined up for the bathroom or a ride!

Was this your first time visit to Japan? Last week of March and first week of April is Japanese Spring Break, schools are off because Japanese school year starts from April. Many tourist places are busy and addition to that there are many non-Japanese visitors due to Cherry Blossom Season. You were one of many non-Japanese flocked into Japan during Cherry Blossom Season. However, OP has asked New Year vs. Japanese Spring Break. As far as places being busy are concerned, New Year will not be any better and likely New Year will be worse than Japanese Spring Break.

During New Year some places and restaurants will be closed, depending on location many places will be closed during New Year. Which is not the case during Japanese Spring Break. Those places open during New Year will be very busy. Not all restaurants will be open during New Year, for example many Sushi restaurants will be closed because Tokyo fish market is closed during New Year. Those few restaurants open during New Year will be extremely busy.

When it comes to comparing New Year and Spring Break in Japan, although you have experienced that places are busy during Japanese Spring Break the situation can be worse during New Year.

as i said...gong show!

also consider that the government wants to double its tourism targets....and kyoto was a mess in early march. how horrible will it get.