As someone who is actually in their 30s, I think there are some great ASX shares that could be great long-term buys today.

These impressive stocks could be top picks for potential capital growth, with any passive income a useful bonus.

While dividend-paying businesses are appealing, it can be less tax-efficient for a full-time worker to receive a significant portion of the returns as income because that can lead to higher tax payments. Overall, I'm looking for businesses that could provide the strongest total net returns.

With that in mind, let's look at two businesses I recently invested in my portfolio.

Centuria Group Ltd (ASX: CNI)

High interest rates have been a significant headwind for real estate-related businesses. Centuria is a real estate fund manager who manages several unlisted property funds and real estate investment trusts (REITs), such as Centuria Industrial REIT (ASX: CIP) and Centuria Office REIT (ASX: COF).

For starters, the business could be one of the biggest beneficiaries of any interest rate cuts by the RBA. It could reduce the cost of debt, increase the valuation of properties (and grow Centuria's management fees), and help encourage investors to allocate more money to the fund manager to manage.

I'm also excited about the ASX share's increasing exposure to data centres.

It owns a 50% stake in ResetData, a business that's described as a "new-generation data service provider" that utilises liquid cooling technology.

ResetData is going to build what it calls an AI-F1 supercomputer in a Melbourne CBD office building. This supercomputer will provide instant access to enterprise-grade AI capabilities without capital investment, a 40% reduction in computing costs, Nvidia-certified AI solutions, minimal latency (thanks to the CBD location), 45% lower emissions, and zero wastewater, supporting ESG objectives.

I really like this partnership for three reasons. First, Centuria can benefit from the growth of ResetData's business (due to its 50% stake). Second, ResetData's tenancy of office space unlocks stronger rental profits. Third, it can help increase the value of the office buildings (helping Centuria's management fees).

This ASX share was one of my latest investments.

Tuas Ltd (ASX: TUA)

Tuas is one of the largest ASX growth share positions in my portfolio because I am excited about its future.

It's an ASX telco share that's seeking to grow rapidly in Asia. In the recent AGM update, the company noted it had reached 1.1 million subscribers in Singapore, which is a really impressive number considering it's only been in the country for a few years.

The company is regularly growing its profit and operating profit (EBITDA) at a pleasing double-digit pace, which helps compounding. In the first quarter of FY25, its revenue jumped 33% to $35.5 million, and EBITDA climbed 46% to $16.1 million.

Another pleasing factor about the business is its rising profit margins. Investors usually value a business on its profit potential, so if profit can rise even faster than revenue, it can significantly increase its underlying value. Its EBITDA margin improved to 45% in the FY25 first quarter.

While nothing is certain, I'm excited by the company's potential to lengthen its growth runway by expanding to another Asian country, such as Malaysia or Indonesia. This could help the business become a much larger ASX share over time.