As an undergraduate, should I graduate 1.5 to 2 years early with little research experience or 1 year early with a decent amount of research? So I am an undergraduate student in my third semester and I am mostly done with my double major in Pure and Applied Mathematics/Statistics. I will be done with the requirements for my bachelors by my fifth semester at the latest.

If I want to go for a PhD in Pure Math, would I be better off graduating after my 5th semester or pushing some classes back, taking graduate level classes and seminars in my 6th semester and doing an undergraduate thesis? I have some research done and will be doing more next semester, but that is nowhere near what I would do for the honors thesis. 

Alternatively, I could go all out next semester and graduate then. However this would leave me very little time to study for the subject GRE (I am good with the general GRE) and to actually apply for schools due to how busy I will be.

I tried to make this a good question by including as much information as I thought was relevant, but if there are any questions or anything I forgot to mention then please let me know.

Does anyone have advice?
For the title question, graduating 1 year early and accomplishing more is definitely better than graduating 1.5 or 2 years early, and accomplishing less. In fact, there's a strong case to be made for taking four years and accomplishing as much as you can. In PhD admissions, you'll be competing against people who were also ahead of the game in their first few semesters, but stayed in school and kept gathering feathers in their cap. Some of these feathers will be more impressive than graduating early. Also, more time as an undergrad means more chances for professors to get to know you, and this is what translates into good letters of recommendation.

Now, that is all general advice. Factors particular to your situation may tilt the balance in favor of it making sense to graduate early. I would recommend talking this over with your professors, because they know your record and can give you realistic advice about your prospects after graduating in X semesters, for various values of X.