I flew on United again during the pandemic and found it to be a leading contender for best US airline to fly in 2021 - here's why

My United journey started at Denver International Airport where I'd catch the 7:50 a.m. flight to Houston.

I headed to the check-in area and immediately noticed that it had been entirely overhauled with social distancing measures.

Each check-in station had plexiglass partitions separating United staff from passengers...

And kiosks had plastic dividers between them with the option for "touchless check-in" by using a mobile device if a user didn't want to touch the screen.

Even signage above the check-in area was promoting proper face-covering rules. It was an impressive overhaul and more so than I've seen from some competitors.

Before I even got to the kiosk, I was required to acknowledge United's face covering rule...

And the health declaration when I checked in online. I had to affirm that I hadn't tested positive for COVID-19 in the past three weeks nor had I been exposed to the virus, as well as been experiencing any symptoms.

I also had to confirm that I wasn't awaiting COVID-19 test results and no other airline had denied me boarding. These requirements were definitely more strict than others I'd seen in my travels.

United is also offering contact tracing so customers are asked to provide their contact information; though, the program is optional.

My flight to Houston was for a special occasion, United's first Boeing 737 Max passenger flight since March 2019, and it was nearly sold out as aviation enthusiasts flocked to Denver to be on the first flight.

United informed me that the flight was filling up at check-in and I was offered the option to change to a different flight for free. It's a nice gesture but I've found it's rarely helpful.

There was no shortage of alternate options on the Denver-Houston route but other routes don't have as many backup options since the pandemic forced airlines to reduce flights. And there's no guarantee any of these flights wouldn't also fill up with passengers.

The gate area for my flight featured many of the same measures as check-in, including a banner reminding passengers to wear face coverings and social distance, as well as highlighting United's partnership with Clorox and the Cleveland Clinic,

Gate counters were also covered with plexiglass partitions and had additional details about the airline's new safety protocols.

Social distancing placards dotted the carpet and continued into the jetway. United had done a great job of ensuring multiple layers of precautions here.

Before boarding, gate agents reminded passengers that wearing masks are now part of federal law and they'd be required to be worn at all times, except when eating and drinking. A refusal could mean denial of boarding and civil penalties.

Digital signage above the gate also explained the airline's new boarding procedure and additional social distancing measures.

The flight was then boarded from the back of the plane to the front to help with social distancing. Pre-boarding was still offered and first class flyers along with United elites were still allowed to board first.

More placards lined the jetway and though passengers rarely adhere to the six-feet rule in the jetway, the placards serve as a nice gesture to show the airline is being proactive during the pandemic.

Flight attendants welcomed us on the flight and gave us a sanitary wipe to clean the seats.

The cabin, however, appeared spotless already.

United, like most US airlines, disinfects aircraft via "fogging" with an electrostatic sprayer before each flight.

I had no concerns whatsoever with cabin cleanliness. It also helped that this was essentially a brand-new plane as no paying passengers had flown on it since March 2019.

Flying on a United Airlines Boeing 737 Max 9. Thomas Pallini/Insider

I had no concerns whatsoever with cabin cleanliness. It also helped that this was essentially a brand-new plane as no paying passengers had flown on it since March 2019.

The back-to-front system also appeared to work worked as there were not many passengers I had to walk past, except in first class and the first few rows of economy where United elites were sat.

My seat, 30A, was a window seat towards the back of the plane and I was among the first to board.

I found my seat to be impeccably clean, rendering the wipe virtually useless.

Even the tray table was spotless; although, that's par for the course on a "new" aircraft like this one.

This aircraft, in particular, has no seat-back screens and United had removed all the literature beyond the safety card.

Flight attendants once again stressed the importance of mask-wearing during the pre-departure briefing. United has banned over 600 passengers as of mid-January for not wearing masks, the second most of any US airline that shared its statistics with Insider.

Soon enough, we were off on our two-hour journey to Houston.

Flight attendants began the in-flight service shortly after takeoff, armed with masks and gloves. Not all airlines require their flight attendants to wear gloves during the service, surprisingly.

Each passenger was given this snack bag, as is the case on most US airlines still conducting an in-flight service.

Inside were the essentials including a bottle of water, Stroopwafel, pretzels, and another sanitary wipe.

And it didn't stop there as we were also offered a soft drink. I was pleasantly shocked as this was the first time I'd be given something other than plain water while flying during the pandemic.

It was a nice touch and I was glad to see a semblance of normal. Plus, the Stroopwafel is among my favorite in-flight snacks.

I took a quick walk around the cabin to see how well United's warnings about mask-wearing were heeded by the passengers.

All in all, the strict warnings did appear to work as most were masked up during the flight.

The most egregious offense I saw was not having the mask over the nose but that was rare.

It was truly a normal flight with no major issues.

Soon enough, it was time to land in Houston.

United often deplanes by rows but we didn't on this flight. Many passengers were rushing to make connecting flights as we'd been slightly delayed leaving Denver.

Overall, it was an enjoyable flight and made me want to fly United again.