Buy the Samsung HW-B400F Soundbar.

It's the only one of the three that actually gives you bass, a growth path, and no history of dying young.

What was compared

1. Bass you can actually feel
The B400F ships with a built-in subwoofer. The Bose TV Speaker and the Assistrust bar are both flat 2.0 setups with no dedicated bass driver, so explosions and game rumble stay thin no matter how loud you push them.
2. Bose owners report it just stops working
Multiple Bose TV Speaker buyers describe it dying within two years, one after only four months, with weak support from Bose when it happened. Nothing in the data suggests the Samsung has that failure pattern.
3. Room to grow, unlike either rival
The B400F supports Surround Sound Expansion, so you can add rear speakers later if you want a bigger setup. Bose and Assistrust are both dead-end 2.0 bars with no upgrade path once you outgrow them.
4. A name behind it when things go wrong
One Assistrust owner reports a remote that stopped adjusting volume with no clear replacement path, a sign of the thin support a no-name label offers. Samsung backs the B400F with an established service and parts network.
5. Yes it costs more. Buy it anyway.
The B400F sits at $89.99 against Assistrust's $49.99 and Bose's $53.99, a real gap. But that extra $30 to $40 buys an actual subwoofer, an expansion path, and a brand that isn't reporting units dying in year two.