It depends on you definition of BEST, Your needs and what you can afford. Crosman makes rifles for use at all different levels of users. They also make rifles in different calibers like .177, .20 and .22 caliber. Crosman also owns Benjamin airguns.
Let me give you some different things to look at. BB guns & rifles have smooth bore barrels (like a straw). BB are not accurate beyond 15 to 20 feet. Smooth bore barrels let the BB tumble as it flies through the air. Pellet rifles have rifled bore barrels. This makes the pellet spin as it leaves the barrel and it will fly straighter and further,
C02 guns usually are the weakest powerplants. But provide the most shots per powerlett (C02 cylinder). Pump is the next strongest, but you will get tired of pumping. Spring and Nitro piston are stronger but are only made in single shot design. PCP (PerCharged Pneumatic) are the strongest but are very expensive. They also require a Scuba tank to charge them to 2000 to 3000 psi. The cost is usually around $400 and up.
I suggest you look at the link I have attached below and read some of the reviews by owners and determine the best rifle for you.
See the link below for your answer
See the CROSMAN Link below.
See the link below for the Owners Manual for the Crosman 1077 air rifle
Crosman no longer has parts for this rifle. However there are independent shops that repair older Crosman air guns. Crosman offers a free service to locate these shops. see the link below.
Airgundepot.com is your best bet. The Crosman Phantom 1000 air rifle has received high reviews and has a smooth bore.
Crosman does. see the link below for the parts list and how to contact Crosman.
See the Crosman link below.
In 1977 The Benjamin Rifle company purchased Sheridan air gun company. In 1992 Crosman purchased Benjamin. So now Crosman owns both Benjamin and Sheridan.
Crosman still has parts for this rifle. contact Crosman at the link below (Customer service) and order the parts you need.
Crosman started making the Raven's in 2008.
It all depends on what is wrong with it.
You can still order 1077 parts from Crosman in New York. See the parts and owners manuals link below. Then contact Crosman Customer service and order your parts.