Need to purchase a battery charger, what type do you recommend?

It really depends on what you are going to use it for. I use a small charger when I just want to maintain a battery. I use mine also for keeping the battery up while I am performing computer diagnostics on a vehicle without the engine running.
The charger I use is a DSR Pro Series Model PSC 12500A It is fully automatic and has a 125 Amp boost. It is very compact and easy to use. It has LED's that tell you the condition of your battery, the charging rate, etc.
I purchased mine from Matco Tools (Matco part number MIC1200) It is available through many local parts suppliers as well as online automotive parts and equipment suppliers.

This all depends on what you are trying to do, if you have a car that sits alot you may what a battery tender that you can leave connected to battery until you use the car, this will keep battery charged as needed and shut off when charged, if want a battery charger to have around then i would get a shop type, this would be one that will do 6-12 volts and has settings for 12 low , 12 high and 12 jump start, it will also have 6volt low and high but not really needed, and will have a timer so you can set it and leave it and it will shut down at the time it is set for, for example go to a napa web site,and check out these part #sthis is a full use one 85-810 or a tender one is730-5033 or a small charger 730-5034. you can also check out sears and get a craftsman charger. hope this helps,