Well, currently a hive tyrant with wings and twin-linked brainleech devourers is the most durable and shooty tyranid unit in the game short of maybe a barbed hierodule or other super heavy. They're generally recognized to stand head and shoulders over every other tyranid
MC (or maybe even tyranid unit) in the codex.
That said, it's really up to you. The swarm lord is good at what he does if he can get there, but he'll generally be shot up before he reaches combat in competitive environments. In more friendly games, his chances of reaching combat are better, especially if you give him some hive guard.
The regular non-winged tyrant is basically a worse-but-cheaper swarmlord. He'll lack the extra punch and special shenanigans of the swarmlord, but the price difference will pay for about two of the hive guard he may or may not be hanging out with (depending on what gear you give him). I feel I ought to mention that you don't have to give your tyrant wings to benefit from the
TL devourers, though you will lose some survivability.
For competitive settings, flyrant or bust. Otherwise, make the giant monster *you* want to see on the table.