After about 5 months of owning GTA V and Online (having been given the game as a gift at Christmas), I've managed to rise up the ranks in GTA Online, and am currently a Level 33. Through this period, I found many vehicles to be very good for new players, and I'm still finding ones that would be good for new players even now.
All of these cars can either be purchased on the In-game internet, or can be readily found 'in the wild' on the road, ripe for the taking!
This list will probably expand as I find more good choices, but for now, here's the Top 5, in ascending order, with 5 considered the best out of the set.
1. Dubsta - This SUV is easy to insure and relatively easy to find on the road, although for some people it may be more common than for others. For me, I found that they tended to spawn more often on certain days of the week. The Dubsta's got a reasonable stock engine and packs a punch when it comes to ramming things out of the way. There's also a lot of customizability potential at Los Santos Customs, too.
2. Sultan - An ideal street racer for new players, the Sultan is relatively cheap to buy and also appears fairly often in traffic. Since the Sultan RS is also now available for players through an upgrade at Benny's Original Motor Works, It's worth purchasing a Sultan with the intention of upgrading it to an RS later on.]
3. Ruiner - This car was already competent in GTA IV, but it was made much better when it was included in GTA V and GTA Online. Since you can't purchase it, you'll have to find one on the road, but like the Dubsta they're very easy to insure. There's also a reasonable amount of mods you can give it to make it look the part.
4. Sabre Turbo - While it does have a tendency to fishtail quite a fair bit if handled incorrectly, this muscle car packs both power and class. While the modifications at LS Customs are a bit limited, you can also upgrade this to a Sabre Turbo Custom at Benny's, giving you a wider array of upgrades to give to it. On its own, this car is reasonable in just about every department, and that engine sounds divine.
5. F620 - In a game where most players show off their souped up and incredibly nimble super cars, it's easy to feel a bit left out. Fortunately, the F620 is an ideal choice if you want to get into the 'in-crowd'. While classed as a grand tourer, the F620 is fast and powerful enough to keep up with most of its fellow racers, and it's also got a lot of class too. It's also the only supercar/grand tourer in Online that can be taken off the road and insured, so you don't even need to shell out the full price on the internet to obtain it.
So, that's all for now! I may well end up updating this list fairly often, as mentioned in the introduction.
See you all soon.